Practice Test


1) How much work does the road do on the cycle?


2) How much work does the cycle do on the road?


3) The sign of work done by a force on a body is important to understand. For
(i) work done by a man in lifting a bucket out of a wall by means of a rope tide to the bucket
(ii) work one by friction on a body sliding down an inclined plane
(iii) work done by a applied force on a body moving on a rough horizontal plane with uniform velocity
(iv) work done by the resistive force of air on a vibrating pendulum in bringing it to rest. Choose the sign of work done


4) When a conservative force does positive work on a body; the potential energy of the body


5) Two identical ball bearings in contact with each other and resting on a frictionless table are hit head on by another ball bearing of the same mass moving initially with a speed v. If the collision is elastic, which of the following is a possible result of the collision?


6) A trolley of mass 300 kg carrying a sandbag of 25 kg is moving uniformly with a speed of 36 km/h on a frictionless track. After a while, sand starts leaking out of a hole on the floor of the trolley at the rate of 0.05 kg/s. Speed of the trolley when the entire sand bag is empty is


7) The linear momentum of a body is increased by 50%. The kinetic energy will be increased by


8) Two masses of 1 g and 9 g are moving with equal kinetic energies. The ratio of the magnitudes of their respective linear momentum is


9) Change in magnitude of velocity of bead between point A and B is


10) Time taken by bead to move between points A and B is


11) The average force exterted by the bead on the part AB of the wire is


12) A machine which is 70% efficient raises a 10 kg body through a certain distance and spends 100 J of energy. The body is then released. On reaching the ground, the kinetic energy of the body will be


13) A glass marble dropped from a certain height above the horizontal surface reaches the surface in time t and then continues to bounce up and down. The time in which the marble finally comes to rest is


14) A nucleus ruptures into two nuclear parts which have their velocity ratio equal to 2 : 1. The ratio of their respective nuclear sizes (nuclear radii) is


15) Two billiard balls of the same size and mass are in contact on a billiard table. A third ball of the same size and mass strikes them symmetrically and remains at rest after the impact. The coefficient of restitution between the balls is


16) A stone is dropped from the top of a tall tower. The ratio of the kinetic energy of the stone at the end of three second to the increase in the kinetic energy of the stone during the next three second is


17) The negative of the space rate of change of potential energy is equal to


18) A conservative force moves a body round a closed path. Work done will be


19) Statement 1 : If the work done by force other than conservative forces is zero, then mechanical energy is conserved.
Statement 2 : The work done by non-conservative forces is always negative.


20) As the block slides down, which of the following quantities associated with the system remains conserved?


21) If there would have been friction between wedge and block, which of the following quantities would still remain conserved?


22) If there is no friction anywhere, the speed of the wedge, as the block leaves the wedge, is


23) A 2 kg body is dropped from a height of 0.4 m on a spring of force constant 2000 N/m. The maximum compression of the spring is:


24) A projectile is fired with kinetic energy 1 kJ. If its range maximum the kinetic energy at the highest point is:


25) When K.E. of the body is increased by 300%, the momentum of the body is increased by:


26) Two masses of 1 g and 4 g are moving with equal kinetic energy. The ratio of their linear momenta is:


27) The momentum of body is numerically equal to its K.E. What is the velocity of body?


28) A tennis ball dropped from a height of 2 m rebounds only 1.5 m after hitting the ground. What fraction of energy is lost in the impact?


29) A light and a heavy body have equal K.E. which one has greater momentum?


30) A uniform chain of length 'L' and mass M is lying on a smooth table and one-third of its length is hanging vertically down over the edge, the work done to pull the hanging part on to the table is:


31) A ball falls freely from a height of 10 m. If 40% of the energy is lost due to impact, the ball will go up to a height (after one impact) given by:


32) A solid ball of density half that of water falls freely under gravity from a height of 19.6 m and then enters water. Up to what depth it will sink? Also find how much time will the ball take to come again to the water surface? (Neglect air and water resistances);


33) A body falling freely under gravity has a P.E. equal to 9 times the K.E. at a particular instant. When the velocity of the body is doubled than the velocity at a certain instant, the ratio between P.E. and K.E. will be:


34) A bullet, when fired at a fixed plate has its velocity decreased by 50% after penetrating through 30 cm of its thickness. What is the additional thickness required for the plate so that the bullet may just comes to rest after penetrating it?


35) If the force acting on a body is inversely proportional to its speed the K.E. of a body is:


36) A ball falling from a height of 5 m rebounds to 1.8 m height. Then the ratio of velocities of the ball after and before rebound is:


37) A body A experiences perfectly elastic collision with a stationary body B. If after collision the bodies fly apart in the opposite direction with equal velocities, the mass ratio of A and B is:


38) A heavy nucleus at rest breaks into two fragments which fly off with velocities 8 : 1. The ratio of radii of the fragments is:


39) A bullet fired into a fixed target loses 20% of its K.E. in penetrating 1 cm. Find the total distance penetrated by bullet before it comes to rest:


40) A running man has half the kinetic energy of that of a boy of half his mass. The man speeds up by one metre per second and then has the same kinetic energy as that of the boy. What are the original speeds of the boy and man?


41) Which of the following is true?


42) A body of mass 5 kg has momentum of 10 kg m/s. When a force of 0.2 N is applied on it for 10 seconds, what is the change in its kinetic energy?


43) A body of mass 5 kg explodes into 3 fragments having masses in ratio of 2 : 1 : 1. The fragments with equal masses fly in merely far direction with speed 15 m/sec. What will be the velocity of lighter fragment:


44) A body of mass 10 kg at rest is acted upon simultaneously by two forces 4 N and 3 N at right angles to each other. The kinetic energy of the body at the end of 10 s is:


45) A force 10 N displace an object by 10 m. If work done is 50 J then direction of force makes an angle with direction of displacement:


46) 250 N force is required to raise 75 kg mass with a pulley. If rope is pulled 12 m them the load is lifted to 3m, the efficiency of pulley system will be:


47) A metal ball of mass 2 kg moving with speed of 36 km/hr has a head on collision with a stationary ball of mass 3 kg. If after collision, both the balls move together, then the loss in kinetic energy due to collision is:


48) A motor pump lifts 300 kg of water per minute from a well 20 m deep and delivers to height of 20 m. Its power is :


49) The kinetic energy of a body becomes four times its initial value. The new linear momentum will be:


50) Potential energy in a spring when stretched by 2 cm is U. Its potential energy, when stretched by 10 cm is:


51) An ideal spring with spring-constant k is hung from the ceilling and a block of mass M is attached to its lower end. The mass is released with the spring initially unstretched. Then the maximum extension in the spring is:


52) A 50 kg man with 20 kg load on his head climbs up 20 steps of 0.25 m height each. The work done in climbing is:


53) A pump motor is used to deliver water at a certain rate from a given pipe. To obtain in twice as much water from the same pipe in the same time, power of the motor has to be increased to:


54) If kinetic energy of a body is increased by 300 percent, then percentage change in momentum will be:


55) If force and displacement of particle in the direction of force are doubled. Work would be:


56) A machine, which is 75% efficient, uses 12 J of energy in lifting up a 1 kg mass through a certain distance. The mass is then allowed to fall through that distance. The velocity at the ends of its fall is (in m/s):


57) A body of mass 2 kg makes an elastic collision with another body at rest and continues to move in the original direction with one fourth of its original speed. The mass of the second body which collides with the first body is:


58) A quarter horse power motor runs at a speed of 600 r.p.m. Assuming 40% efficiency the work done by the motor in one rotation will be:


59) A car of mass 1000 kg accelerates uniformly from rest to a velocity of 54 km/hour in 5 s. The average power of the engine during this period in watts is (neglect friction) :


60) An elevator is run by the cables at constant speed. The total work done by the elevator is:


61) A wire suspended vertically from one of its ends is stretched by attaching a weight of 200 N to the lower end. The weight stretches the wire by 1mm. Then the elastic energy stored in the wire is:


62) When a long spring is stretched by 2 cm, its potential energy is U. if the spring is stretched by 10 cm, the potential energy stored in it will be:


63) A neutron makes a head-on elastic collision with a stationary deuteron. The fractional energy loss of the neutron in the collision is:


64) Two masses 1 g and 4 g are moving equal kinetic energies. The ratio of magnitudes of their momentum is:


65) A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of:


66) A ball is dropped from a height of 20 cm. Ball rebounds to a height of 10 cm. What is the loss of energy?


67) A bomb of mass 3.0 kg explodes in air into two pieces of masses 2.0 kg and 1.0 kg. The smaller mass goes at a speed of 80 m/s. The total energy imparted to the two fragments is:


68) One milligram of matter is converted into energy. The energy released will be:


69) If the kinetic energy of a body increases by 0.1%, the percentage increase of its momentum will be:


70) A ball is released from the top of the tower. The ratio of work done by force of gravity in first, second and third second of the motion of the ball is:


71) A shell of mass 200 gm is ejected form a gun of mass 4 kg by an explosion that generates 1.05 kJ of energy. The initial velocity of the shell is:


72) A uniform metal chain is placed on a rough table such that one end of it hangs down over the edge of the table. When one third of its length hangs over the edge, the chain starts sliding. Then the coefficient of static friction is:


73) Potential energy of a long spring when stretched by 2 cm is U. What is the P.E. when spring is stretched by 8 cm?


74) An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted of water?


75) A ball moving with velocity 2 m/s collides head on with another stationary ball of double the mass. If the coefficient of restitution is 0.5, then their velocities (in m/s) after collision will be:


76) An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a velocity of 2m/s. The mass per unit length of water in the pipe is 100 kg/m. What is the power of the engine?


77) The potential energy of a system increases if work is done:


78) If the unit of force and length each be increased by four times, then the unit of energy is increased by


79) A man pushes a wall and fails to displace it. He does


80) The same retarding force is applied to stop a train. The train stops after 80 m. If the speed is doubled, then the distance will be


81) A body moves a distance of 10 m along a straight line under the action of a force of 5 N. If the work done is 25 joules, the angle which the force makes with the direction of motion of the body is


82) You lift a heavy book from the floor of the room and keep it in the book-shelf having a height 2 m. In this process you take 5 seconds. The work done by you will depend upon


83) A body of mass m kg is lifted by a man to a height of one metre in 30 sec. Another man lifts the same mass to the same height in 60 sec. The work done by them are in the ratio


84) Which of the following is a scalar quantity


85) A force of 5 N acts on a 15 kg body initially at rest. The work done by the force during the first second of motion of the body is


86) The work done against gravity in taking 10 kg mass at 1m height in 1sec will be


87) A body of mass 10kg at rest is acted upon simultaneously by two forces 4 N and 3N at right angles to each other. The kinetic energy of the body at the end of 10 sec is


88) A cylinder of mass 10kg is sliding on a plane with an initial velocity of 10m/s. If coefficient of friction between surface and cylinder is 0.5, then before stopping it will describe


89) A 50kg man with 20kg load on his head climbs up 20 steps of 0.25m height each. The work done in climbing is


90) In an explosion a body breaks up into two pieces of unequal masses. In this


91) Which of the following is a unit of energy


92) If force and displacement of particle in direction of force are doubled. Work would be


93) A uniform chain of length 2m is kept on a table such that a length of 60cm hangs freely from the edge of the table. The total mass of the chain is 4kg. What is the work done in pulling the entire chain on the table


94) A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle, the motion of the particle takes place in a plane. It follows that


95) A ball of mass m moves with speed v and strikes a wall having infinite mass and it returns with same speed then the work done by the ball on the wall is


96) The kinetic energy acquired by a body of mass m is travelling some distance s, starting from rest under the actions of a constant force, is directly proportional to


97) A man starts walking from a point on the surface of earth (assumed smooth) and reaches diagonally opposite point. What is the work done by him


98) It is easier to draw up a wooden block along an inclined plane than to haul it vertically, principally because


99) Two bodies of masses 1 kg and 5 kg are dropped gently from the top of a tower. At a point 20 cm from the ground, both the bodies will have the same


100) A ball is released from the top of a tower. The ratio of work done by force of gravity in first, second and third second of the motion of the ball is


101) A spring of force constant 10 N/m has an initial stretch 0.20 m. In changing the stretch to 0.25 m, the increase in potential energy is about


102) The potential energy of a certain spring when stretched through a distance ‘S’ is 10 joule. The amount of work (in joule) that must be done on this spring to stretch it through an additional distance ‘S’ will be


103) Two springs of spring constants 1500 N/m and 3000 N/m respectively are stretched with the same force. They will have potential energy in the ratio


104) A spring 40 mm long is stretched by the application of a force. If 10 N force required to stretch the spring through 1 mm, then work done in stretching the spring through 40 mm is


105) The force constant of a wire is k and that of another wire is When both the wires are stretched through same distance, then the work done


106) A body of mass 0.1 kg moving with a velocity of 10 m/s hits a spring (fixed at the other end) of force constant 1000 N/m and comes to rest after compressing the spring. The compression of the spring is


107) A spring of force constant 800 N/m has an extension of 5cm. The work done in extending it from 5cm to 15 cm is


108) When a spring is stretched by 2 cm, it stores 100 J of energy. If it is stretched further by 2 cm, the stored energy will be increased by


109) A spring when stretched by 2 mm its potential energy becomes 4 J. If it is stretched by 10 mm, its potential energy is equal to


110) A mass of 0.5kg moving with a speed of 1.5 m/s on a horizontal smooth surface, collides with a nearly weightless spring of force constant k=50 N/m . The maximum compression of the spring would be


111) A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x is proportional to


112) A spring with spring constant k when stretched through 1 cm, the potential energy is U. If it is stretched by 4 cm. The potential energy will be


113) If a long spring is stretched by 0.02 m, its potential energy is U. If the spring is stretched by 0.1 m, then its potential energy will be


114) The spring extends by x on loading, then energy stored by the spring is :
(if T is the tension in spring and k is spring constant)


115) Which one of the following is not a conservative force


116) Work done in raising a box depends on


117) A light and a heavy body have equal momenta. Which one has greater K.E


118) A body at rest may have


119) If the momentum of a body is increased n times, its kinetic energy increases


120) When work is done on a body by an external force, its


121) The bob of a simple pendulum (mass m and length l) dropped from a horizontal position strikes a block of the same mass elastically placed on a horizontal frictionless table. The K.E. of the block will be


122) From a stationary tank of mass 125000 pound a small shell of mass 25 pound is fired with a muzzle velocity of 1000 ft/sec. The tank recoils with a velocity of


123) A bomb of 12 kg explodes into two pieces of masses 4 kg and 8 kg. The velocity of 8kg mass is 6 m/sec. The kinetic energy of the other mass is


124) Two masses of 1 gm and 4 gm are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is


125) If the K.E. of a body is increased by 300%, its momentum will increase by


126) A light and a heavy body have equal kinetic energy. Which one has a greater momentum ?


127) If the linear momentum is increased by 50%, the kinetic energy will increase by


128) A free body of mass 8 kg is travelling at 2 meter per second in a straight line. At a certain instant, the body splits into two equal parts due to internal explosion which releases 16 joules of energy. Neither part leaves the original line of motion finally


129) If the K.E. of a particle is doubled, then its momentum will


130) If the stone is thrown up vertically and return to ground, its potential energy is maximum


131) The energy stored in wound watch spring is


132) A car travelling at a speed of 30 km/hour is brought to a halt in 8 m by applying brakes. If the same car is travelling at 60 km/hour, it can be brought to a halt with the same braking force in


133) Tripling the speed of the motor car multiplies the distance needed for stopping it by


134) If the kinetic energy of a body increases by 0.1%, the percent increase of its momentum will be


135) If velocity of a body is twice of previous velocity, then kinetic energy will become


136) Two bodies A and B having masses in the ratio of 3 : 1 possess the same kinetic energy. The ratio of their linear momenta is then


137) In which case does the potential energy decrease


138) A sphere of mass m, moving with velocity V, enters a hanging bag of sand and stops. If the mass of the bag is M and it is raised by height h, then the velocity of the sphere was


139) The force constant of a weightless spring is 16 N/m. A body of mass 1.0 kg suspended from it is pulled down through 5 cm and then released. The maximum kinetic energy of the system (spring + body) will be


140) Two bodies with kinetic energies in the ratio of 4 : 1 are moving with equal linear momentum. The ratio of their masses is


141) If the kinetic energy of a body becomes four times of its initial value, then new momentum will


142) A bullet is fired from a rifle. If the rifle recoils freely, then the kinetic energy of the rifle is


143) Two bodies of masses 2m and m have their K.E. in the ratio 8 : 1, then their ratio of momenta is


144) A bomb of 12 kg divides in two parts whose ratio of masses is 1 : 3. If kinetic energy of smaller part is 216 J, then momentum of bigger part in kg-m/sec will be


145) A 4 kg mass and a 1 kg mass are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is


146) If the increase in the kinetic energy of a body is 22%, then the increase in the momentum will be


147) If momentum is increased by 20%, then K.E. increases by


148) The kinetic energy of a body of mass 2 kg and momentum of 2 Ns is


149) The decrease in the potential energy of a ball of mass 20 kg which falls from a height of 50 cm is


150) An object of 1 kg mass has a momentum of 10 kg m/sec then the kinetic energy of the object will be


151) A ball is released from certain height. It loses 50% of its kinetic energy on striking the ground. It will attain a height again equal to


152) A 0.5 kg ball is thrown up with an initial speed 14 m/s and reaches a maximum height of 8.0m. How much energy is dissipated by air drag acting on the ball during the ascent


153) An ice cream has a marked value of 700 kcal. How many kilowatt- hour of energy will it deliver to the body as it is digested


154) A particle of mass 'm' and charge 'q' is accelerated through a potential difference of 'V' volt. Its energy is


155) A running man has half the kinetic energy of that of a boy of half of his mass. The man speeds up by 1m/s so as to have same K.E. as that of the boy. The original speed of the man will be


156) The mass of two substances are 4 gm and 9 gm respectively. If their kinetic energies are same, then the ratio of their momenta will be


157) If the momentum of a body is increased by 100%, then the percentage increase in the kinetic energy is


158) If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest


159) A bomb of mass 9kg explodes into 2 pieces of mass 3kg and 6kg. The velocity of mass 3kg is 1.6 m/s, the K.E. of mass 6kg is


160) Two masses of 1kg and 16kg are moving with equal K.E. The ratio of magnitude of the linear momentum is


161) Two bodies moving towards each other collide and move away in opposite directions. There is some rise in temperature of bodies because a part of the kinetic energy is converted into


162) A particle of mass m at rest is acted upon by a force F for a time t. Its Kinetic energy after an interval t is


163) The potential energy of a weight less spring compressed by a distance a is proportional to


164) Two identical blocks A and B, each of mass 'm' resting on smooth floor are connected by a light spring of natural length L and spring constant K, with the spring at its natural length. A third identical block 'C' (mass m) moving with a speed v along the line joining A and B collides with A. the maximum compression in the spring is


165) Two bodies of masses m and 4 m are moving with equal K.E. The ratio of their linear momentums is


166) The kinetic energy of a body of mass 3 kg and momentum 2 Ns is


167) A ball of mass 2kg and another of mass 4kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of


168) Four particles given, have same momentum which has maximum kinetic energy


169) A body moving with velocity v has momentum and kinetic energy numerically equal. What is the value of v


170) If a man increase his speed by 2 m/s , his K.E. is doubled, the original speed of the man is


171) Which among the following, is a form of energy


172) A body is moving with a velocity v, breaks up into two equal parts. One of the part retraces back with velocity v. Then the velocity of the other part is


173) If a shell fired from a cannon, explodes in mid air, then


174) Masses of two substances are 1 g and 9 g respectively. If their kinetic energies are same, then the ratio of their momentum will be


175) A body of mass 5 kg is moving with a momentum of 10 kg-m/s. A force of 0.2 N acts on it in the direction of motion of the body for 10 seconds. The increase in its kinetic energy is


176) If the momentum of a body increases by 0.01%, its kinetic energy will increase by


177) 1 a.m.u. is equivalent to


178) A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It slides down a smooth surface to the ground, then climbs up another hill of height 30 m and finally slides down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is


179) If a force F is applied on a body and it moves with a velocity v, the power will be


180) A man is riding on a cycle with velocity 7.2 km/hr up a hill having a slope 1 in 20. The total mass of the man and cycle is 100 kg. The power of the man is


181) A 12 HP motor has to be operated 8 hours/day. How much will it cost at the rate of 50 paisa/kWh in 10 days


182) A motor boat is travelling with a speed of 3.0 m/sec. If the force on it due to water flow is 500 N, the power of the boat is


183) An electric motor exerts a force of 40 N on a cable and pulls it by a distance of 30 m in one minute. The power supplied by the motor (in Watts) is


184) An electric motor creates a tension of 4500 newton in a hoisting cable and reels it in at the rate of 2 m/sec. What is the power of electric motor


185) A weight lifter lifts 300 kg from the ground to a height of 2 meter in 3 second. The average power generated by him is


186) A car of mass ‘m’ is driven with acceleration ‘a’ along a straight level road against a constant external resistive force ‘R’. When the velocity of the car is ‘V’, the rate at which the engine of the car is doing work will be


187) The average power required to lift a 100 kg mass through a height of 50 metres in approximately 50 seconds would be


188) From a waterfall, water is falling down at the rate of 100 kg/s on the blades of turbine. If the height of the fall is 100 m, then the power delivered to the turbine is approximately equal to


189) A car of mass 1250 kg is moving at 30m/s. Its engine delivers 30 kW while resistive force due to surface is 750N. What max acceleration can be given in the car


190) A 60 kg man runs up a staircase in 12 seconds while a 50 kg man runs up the same staircase in 11, seconds, the ratio of the rate of doing their work is


191) A pump motor is used to deliver water at a certain rate from a given pipe. To obtain twice as much water from the same pipe in the same time, power of the motor has to be increased to


192) What average horsepower is developed by an 80 kg man while climbing in 10 s a flight of stairs that rises 6 m vertically


193) A car of mass 1000 kg accelerates uniformly from rest to a velocity of 54 km/hour in 5s. The average power of the engine during this period in watts is (neglect friction)


194) A quarter horse power motor runs at a speed of 600 r.p.m. Assuming 40% efficiency the work done by the motor in one rotation will be


195) The power of pump, which can pump 200 kg of water to a height of 50 m in 10 sec, will be


196) From an automatic gun a man fires 360 bullet per minute with a speed of 360 km/hour. If each weighs 20 g, the power of the gun is


197) A man does a given amount of work in 10 sec. Another man does the same amount of work in 20 sec. The ratio of the output power of first man to the second man is


198) The coefficient of restitution e for a perfectly elastic collision is


199) The principle of conservation of linear momentum can be strictly applied during a collision between two particles provided the time of impact is


200) A shell initially at rest explodes into two pieces of equal mass, then the two pieces will


201) A sphere of mass m moving with a constant velocity u hits another stationary sphere of the same mass. If e is the coefficient of restitution, then the ratio of the velocity of two spheres after collision will be


202) Two solid rubber balls A and B having masses 200 and 400 gm respectively are moving in opposite directions with velocity of A equal to 0.3 m/s. After collision the two balls come to rest, then the velocity of B is


203) Two perfectly elastic particles P and Q of equal mass travelling along the line joining them with velocities 15 m/sec and 10 m/sec. After collision, their velocities respectively (in m/sec) will be


204) A lead ball strikes a wall and falls down, a tennis ball having the same mass and velocity strikes the wall and bounces back. Check the correct statement


205) When two bodies collide elastically, then


206) Two balls at same temperature collide. What is conserved


207) A body of mass 5 kg explodes at rest into three fragments with masses in the ratio 1 : 1 : 3. The fragments with equal masses fly in mutually perpendicular directions with speeds of 21 m/s. The velocity of the heaviest fragment will be


208) A body of mass ‘M’ collides against a wall with a velocity v and retraces its path with the same speed. The change in momentum is (take initial direction of velocity as positive)


209) In an elastic collision of two particles the following is conserved


210) A smooth sphere of mass M moving with velocity u directly collides elastically with another sphere of mass m at rest. After collision their final velocities are V and v respectively. The value of v is


211) A body of mass m having an initial velocity v, makes head on collision with a stationary body of mass M. After the collision, the body of mass m comes to rest and only the body having mass M moves. This will happen only when


212) A shell of mass m moving with velocity v suddenly breaks into 2 pieces. The part having mass m/4 remains stationary. The velocity of the other shell will be


213) A rubber ball is dropped from a height of 5 m on a planet where the acceleration due to gravity is not known. On bouncing, it rises to 1.8 m. The ball loses its velocity on bouncing by a factor of


214) A metal ball falls from a height of 32 metre on a steel plate. If the coefficient of restitution is 0.5, to what height will the ball rise after second bounce


215) A ball of mass 10 kg is moving with a velocity of 10 m/s. It strikes another ball of mass 5 kg which is moving in the same direction with a velocity of 4 m/s. If the collision is elastic, their velocities after the collision will be, respectively


216) A body of mass 2 kg collides with a wall with speed 100 m/s and rebounds with same speed. If the time of contact was 1/50 second, the force exerted on the wall is


217) A body falls on a surface of coefficient of restitution 0.6 from a height of 1 m. Then the body rebounds to a height of


218) A ball is dropped from a height h. If the coefficient of restitution be e, then to what height will it rise after jumping twice from the ground


219) A ball of weight 0.1 kg coming with speed 30 m/s strikes with a bat and returns in opposite direction with speed 40 m/s, then the impulse is (Taking final velocity as positive)


220) A billiard ball moving with a speed of 5 m/s collides with an identical ball originally at rest. If the first ball stops after collision, then the second ball will move forward with a speed of


221) If two balls each of mass 0.06 kg moving in opposite directions with speed 4 m/s collide and rebound with the same speed, then the impulse imparted to each ball due to other is


222) A body of mass 50 kg is projected vertically upwards with velocity of 100 m/sec. 5 seconds after this body breaks into 20 kg and 30 kg. If 20 kg piece travels upwards with 150 m/sec, then the velocity of other block will be


223) A steel ball of radius 2 cm is at rest on a frictionless surface. Another ball of radius 4cm moving at a velocity of 81 cm/sec collides elastically with first ball. After collision the smaller ball moves with speed of


224) A space craft of mass M is moving with velocity V and suddenly explodes into two pieces. A part of it of mass m becomes at rest, then the velocity of other part will be


225) A ball hits a vertical wall horizontally at 10m/s bounces back at 10 m/s


226) A bullet of mass 50 gram is fired from a 5 kg gun with a velocity of 1km/s. the speed of recoil of the gun is


227) A body falling from a height of 10m rebounds from hard floor. If it loses 20% energy in the impact, then coefficient of restitution is


228) Two bodies having same mass 40 kg are moving in opposite directions, one with a velocity of 10 m/s and the other with 7 m/s. If they collide and move as one body, the velocity of the combination is


229) A body at rest breaks up into 3 parts. If 2 parts having equal masses fly off perpendicularly each after with a velocity of 12m/s, then the velocity of the third part which has 3 times mass of each part is


230) A particle falls from a height h upon a fixed horizontal plane and rebounds. If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is


231) A big ball of mass M, moving with velocity u strikes a small ball of mass m, which is at rest. Finally small ball obtains velocity u and big ball v. Then what is the value of v


232) A body of mass 5 kg moving with a velocity 10m/s collides with another body of the mass 20 kg at, rest and comes to rest. The velocity of the second body due to collision is


233) A ball of mass m moving with velocity V, makes a head on elastic collision with a ball of the same mass moving with velocity 2V towards it. Taking direction of V as positive velocities of the two balls after collision are


234) A body of mass 2kg makes an elastic collision with another body at rest and continues to move in the original direction with one fourth of its original speed. The mass of the second body which collides with the first body is


235) In the elastic collision of objects


236) A neutron makes a head-on elastic collision with a stationary deuteron. The fractional energy loss of the neutron in the collision is


237) A body of mass m is at rest. Another body of same mass moving with velocity V makes head on elastic collision with the first body. After collision the first body starts to move with velocity


238) A body of mass M moves with velocity v and collides elastically with a another body of mass m (M>>m) at rest then the velocity of body of mass m is


239) A space craft of mass 'M' and moving with velocity 'v' suddenly breaks in two pieces of same mass m. After the explosion one of the mass 'm' becomes stationary. What is the velocity of the other part of craft


240) A ball is allowed to fall from a height of 10 m. If there is 40% loss of energy due to impact, then after one impact ball will go up to


241) Which of the following statements is true


242) A tennis ball dropped from a height of 2 m rebounds only 1.5 m after hitting the ground. What fraction of its energy is lost in the impact


243) A body of mass m moving with velocity v makes a head-on collision with another body of mass 2 m which is initially at rest. The loss of kinetic energy of the colliding body (mass m) is


244) The quantities remaining constant in a collision are


245) An inelastic ball is dropped from a height of 100 m. Due to earth, 20% of its energy is lost. To what height the ball will rise


246) A ball is projected vertically down with an initial velocity from a height of 20 m onto a horizontal floor. During the impact it loses 50% of its energy and rebounds to the same height. The initial velocity of its projection is


247) A tennis ball is released from height h above ground level. If the ball makes inelastic collision with the ground, to what height will it rise after third collision


248) A sphere collides with another sphere of identical mass. After collision, the two spheres move. The collision is inelastic. Then the angle between the directions of the two spheres is


249) A particle of mass m moving eastward with a speed v collides with another particle of the same mass moving northward with the same speed v. The two particles coalesce on collision. The new particle of mass 2m will move in the north-easterly direction with a velocity


250) The coefficient of restitution e for a perfectly inelastic collision is


251) When two bodies stick together after collision, the collision is said to be


252) A bullet of mass a and velocity b is fired into a large block of mass c. The final velocity of the system is


253) A completely inelastic collision is one in which the two colliding particles


254) A bullet hits and gets embedded in a solid block resting on a horizontal frictionless table. What is conserved ?


255) A body of mass 2 kg moving with a velocity of 3 m/sec collides head on with a body of mass 1 kg moving in opposite direction with a velocity of 4 m/sec. After collision, two bodies stick together and move with a common velocity which in m/sec is equal to


256) A body of mass m moving with a constant velocity v hits another body of the same mass moving with the same velocity v but in the opposite direction and sticks to it. The velocity of the compound body after collision is


257) 9. A body of mass m moving with a constant velocity v hits another body of the same mass moving with the same velocity v but in the opposite direction and sticks to it. if another body is at rest, then velocity of the compound body after collision is


258) A bag (mass M) hangs by a long thread and a bullet (mass m) comes horizontally with velocity v and gets caught in the bag. Then for the combined (bag + bullet) system


259) A 50 g bullet moving with velocity 10 m/s strikes a block of mass 950 g at rest and gets embedded in it. The loss in kinetic energy will be


260) A particle of mass m moving with velocity v strikes a stationary particle of mass 2m and sticks to it. The speed of the system will be


261) A moving body of mass m and velocity 3 km/h collides with a rest body of mass 2m and sticks to it. Now the combined mass starts to move. What will be the combined velocity


262) If a skater of weight 3 kg has initial speed 32 m/s and second one of weight 4 kg has 5 m/s. After collision, they have speed (couple) 5 m/s. Then the loss in K.E. is


263) A ball is dropped from height 10 m. Ball is embedded in sand 1 m and stops, then


264) A metal ball of mass 2 kg moving with a velocity of 36 km/h has an head on collision with a stationary ball of mass 3 kg. If after the collision, the two balls move together, the loss in kinetic energy due to collision is


265) A body of mass 2kg is moving with velocity 10 m/s towards east. Another body of same mass and same velocity moving towards north collides with former and coalsces and moves towards north-east. Its velocity is


266) Which of the following is not a perfectly inelastic collision


267) A mass of 20 kg moving with a speed of 10m/s collides with another stationary mass of As a result of the collision, the two masses stick together. The kinetic energy of the composite mass will be


268) The quantity that is not conserved in an inelastic collision is


269) A body of mass 40kg having velocity 4 m/s collides with another body of mass 60kg having velocity 2 m/s. If the collision is inelastic, then loss in kinetic energy will be


270) A bullet of mass m moving with velocity v strikes a block of mass M at rest and gets embedded into it. The kinetic energy of the composite block will be


271) In an inelastic collision, what is conserved


272) Two bodies of masses 0.1 kg and 0.4 kg move towards each other with the velocities 1 m/s and 0.1 m/s respectively, After collision they stick together. In 10 sec the combined mass travels


273) A body of mass 4 kg moving with velocity 12 m/s collides with another body of mass 6 kg at rest. If two bodies stick together after collision, then the loss of kinetic energy of system is


274) Which of the following is not an example of perfectly inelastic collision


275) A ball hits the floor and rebounds after inelastic collision. In this case


276) A uniform chain of length L and mass M is lying on a smooth table and one third of its length is hanging vertically down over the edge of the table. If g is acceleration due to gravity, the work required to pull the hanging part on to the table is


277) If g is the acceleration due to gravity on the earth's surface, the gain in the potential energy of an object of mass m raised from the surface of earth to a height equal to the radius of the earth R, is


278) A lorry and a car moving with the same K.E. are brought to rest by applying the same retarding force, then


279) The kinetic energy acquired by a mass m in travelling a certain distance d starting from rest under the action of a constant force is directly proportional to


280) An open knife edge of mass 'm' is dropped from a height 'h' on a wooden floor. If the blade penetrates upto the depth 'd' into the wood, the average resistance offered by the wood to the knife edge is


281) Consider the following two statements
1. Linear momentum of a system of particles is zero
2. Kinetic energy of a system of particles is zero
Then


282) A body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to


283) A vessel at rest explodes into three pieces. Two pieces having equal masses fly off perpendicular to one another with the same velocity 30 meter per second. The third piece has three times mass of each of other piece. The magnitude and direction of the velocity of the third piece will be


284) A body of mass m moving with velocity v collides head on with another body of mass 2m which is initially at rest. The ratio of K.E. of colliding body before and after collision will be


285) A particle P moving with speed v undergoes a head -on elastic collision with another particle Q of identical mass but at rest. After the collision


286) A set of n identical cubical blocks lies at rest parallel to each other along a line on a smooth horizontal surface. The separation between the near surfaces of any two adjacent blocks is L. The block at one end is given a speed v towards the next one at time . All collisions are completely inelastic, then


287) A particle is dropped from a height h. A constant horizontal velocity is given to the particle. Taking g to be constant every where, kinetic energy E of the particle w. r. t. time t is correctly shown in


288) A particle, initially at rest on a frictionless horizontal surface, is acted upon by a horizontal force which is constant in size and direction. A graph is plotted between the work done (W) on the particle, against the speed of the particle, (v). If there are no other horizontal forces acting on the particle the graph would look like


289) Which of the following graphs is correct between kinetic energy (E), potential energy (U) and height (h) from the ground of the particle


290) The graph between and v is


291) A body moves from rest with a constant acceleration. Which one of the following graphs represents the variation of its kinetic energy K with the distance travelled x ?


292) The diagrams represent the potential energy U of a function of the inter-atomic distance r. Which diagram corresponds to stable molecules found in nature


293) A particle is placed at the origin and a force F = kx is acting on it (where k is positive constant). If =0, the graph U(x) of versus x will be (where U is the potential energy function)


294) Assertion :
A person working on a horizontal road with a load on his head does no work.
Reason :
No work is said to be done, if directions of force and displacement of load are perpendicular to each other.


295) Assertion :
The work done during a round trip is always zero.
Reason :
No force is required to move a body in its round trip.


296) Assertion :
Work done by friction on a body sliding down an inclined plane is positive.
Reason : Work done is greater than zero, if angle between force and displacement is acute or both are in same direction.


297) Assertion : When a gas is allowed to expand, work done by gas is positive.
Reason : Force due to gaseous pressure and displacement (of piston) are in the same direction.


298) Assertion :
A light body and heavy body have same momentum. Then they also have same kinetic energy.
Reason :
Kinetic energy does not depend on mass of the body.


299) Assertion :
The instantaneous power of an agent is measured as the dot product of instantaneous velocity and the force acting on it at that instant.
Reason :
The unit of instantaneous power is watt.


300) Assertion :
The change in kinetic energy of a particle is equal to the work done on it by the net force.
Reason :
Change in kinetic energy of particle is equal to the work done only in case of a system of one particle.


301) Assertion :
A spring has potential energy, both when it is compressed or stretched.
Reason :
In compressing or stretching, work is done on the spring against the restoring force.


302) Assertion : Comets move around the sun in elliptical orbits. The gravitational force on the comet due to sun is not normal to the comet’s velocity but the work done by the gravitational force over every complete orbit of the comet is zero.
Reason : Gravitational force is a non conservative force.


303) Assertion :
The rate of change of total momentum of a many particle system is proportional to the sum of the internal forces of the system.
Reason :
Internal forces can change the kinetic energy but not the momentum of the system.


304) Assertion : Water at the foot of the water fall is always at different temperature from that at the top.
Reason :
The potential energy of water at the top is converted into heat energy during falling.


305) Assertion :
The power of a pump which raises 100 kg of water in 10sec to a height of 100 m is 10 KW.
Reason :
The practical unit of power is horse power.


306) Assertion : According to law of conservation of mechanical energy change in potential energy is equal and opposite to the change in kinetic energy.
Reason : Mechanical energy is not a conserved quantity


307) Assertion : When the force retards the motion of a body, the work done is zero.
Reason :
Work done depends on angle between force and displacement.


308) Assertion :
In an elastic collision of two bodies, the momentum and energy of each body is conserved.
Reason :
If two bodies stick to each other, after colliding, the collision is said to be perfectly elastic.


309) Assertion :
A body cannot have energy without having momentum but it can have momentum without having energy.
Reason : Momentum and energy have same dimensions.


310) Assertion : Power developed in circular motion is always zero.
Reason :
Work done in case of circular motion is zero.


311) Assertion :
A kinetic energy of a body is quadrupled, when its velocity is doubled.
Reason :
Kinetic energy is proportional to square of velocity.


312) Assertion :
A quick collision between two bodies is more violent than slow collision, even when initial and final velocities are identical.
Reason :
The rate of change of momentum determine that force is small or large.


313) Assertion :
Work done by or against gravitational force in moving a body from one point to another is independent of the actual path followed between the two points.
Reason : Gravitational forces are conservative forces


314) Assertion :
Wire through which current flows gets heated.
Reason :
When current is drawn from a cell, chemical energy is converted into heat energy.


315) Assertion : Graph between potential energy of a spring versus the extension or compression of the spring is a straight line.
Reason :
Potential energy of a stretched or compressed spring, proportional to square of extension or compression.


316) Assertion : Heavy water is used as moderator in nuclear reactor.
Reason :
Water cool down the fast neutron.


317) Assertion : Mass and energy are not conserved separately, but are conserved as a single entity called mass-energy.
Reason :
Mass and energy conservation can be obtained by Einstein equation for energy.


318) Assertion :
In case of bullet fired from gun, the ratio of kinetic energy of gun and bullet is equal to ratio of mass of bullet and gun.
Reason :
In firing, momentum is conserved


319) Assertion : Power of machine gun is determined by both, the number of bullet fired per second and kinetic energy of bullets.
Reason :
Power of any machine is defined as work done (by it) per unit time.


320) Assertion :
A work done in moving a body over a closed loop is zero for every force in nature.
Reason :
Work done does not depend on nature of force.


321) Assertion : Mountain roads rarely go straight up the slope.
Reason :
Slope of mountains are large therefore more chances of vehicle to slip from roads.


322) Assertion :
Soft steel can be made red hot by continued hammering on it, but hard steel cannot.
Reason :
Energy transfer in case of soft iron is large as in hard steel.


323) A horizontal force of 5 N is required to maintain a velocity of 2 m/s for a block of 10 kg mass sliding over a rough surface. The work done by this force in one minute is


324) What is the shape of the graph between the speed and kinetic energy of a body


325) When a body moves with some friction on a surface


326) A bullet of mass m moving with velocity v strikes a suspended wooden block of mass M. If the block rises to a height h, the initial velocity of the block will be


327) There will be decrease in potential energy of the system, if work is done upon the system by


328) The slope of kinetic energy displacement curve of a particle in motion is


329) The energy required to accelerate a car from 10 m/s to 20 m/s is how many times the energy required to accelerate the car from rest to 10 m/s


330) The kinetic energy of a body decreases by 36%. The decrease in its momentum is


331) A bomb of mass 3m kg explodes into two pieces of mass m kg and 2m kg. If the velocity of m kg mass is 16 m/s, the total kinetic energy released in the explosion is


332) A neutron travelling with a velocity v and K.E. E collides perfectly elastically head on with the nucleus of an atom of mass number A at rest. The fraction of total energy retained by neutron is


333) A ball moving with speed v hits another identical ball at rest. The two balls stick together after collision. If specific heat of the material of the balls is S, the temperature rise resulting from the collision is


334) A bag of sand of mass M is suspended by a string. A bullet of mass m is fired at it with velocity v and gets embedded into it. The loss of kinetic energy in this process is


335) The potential energy of a certain spring when stretched through a distance ‘S’ is 10 joule. The amount of work (in joule) that must be done on this spring to stretch it through an additional distance ‘S’ will be


336) If the kinetic energy of a body is increased 2 times , its momentum will


337) A steel ball of radius 2 cm is at rest on a frictionless surface. Another ball of radius 4 cm moving at a velocity of 81 cm/sec collides elastically with first ball. After collision the smaller ball moves with speed of


338) A man does a given amount of work in 10 s. Another man does the same amount of work in 20 s. The ratio of the output power of first man to the second man is


339) The force constant of a wire is k and that of another wire is 2k. When both the wires are stretched through same distance, then the work done


340) Consider the following statements. A and B and identify the correct answer given below.
I. Body initially at rest is acted upon by a constant force. The rate of change of its kinetic energy varies linearly with time.
II. When a body is at rest, it must be in equilibrium.


341) A body at rest breaks into two pieces with unequal mass


342) A mass of 50 kg is raised through a certain height by a machine whose efficiency is 90%, the energy is 5000 J. If the mass is now released, its KE on hitting the ground shall be


343) A body of mass 2 kg is projected at 20 m/s at an angle of 60° above the horizontal. Power on the block due to the gravitational force at its highest point is


344) An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a velocity of 2 m/s. The mass per unit length of water in the pipe is 100 kg/m. What is the power of the engine


345) The bodies of masses 1 kg and 5 kg are dropped gently from the top of a tower. At a point 20 cm from the ground, both the bodies will have the same


346) A rubber ball is dropped from a height of 5 m on a planet where the acceleration due to gravity is not known. On bouncing, it rises to1.8 m. The ball loses its velocity on bouncing by a factor of


347) The potential energy of a certain spring when stretched through a distance s is 10 J. The amount of work (in joule) that must be done on this spring to stretch it through additional distance s will be


348) The energy required to accelerate a car from 10 m/s to 20 m/s is how many times the energy required to accelerate the car from rest to 10 m/s


349) A uniform chain of length L and mass M is lying on a smooth table and one third of its length is hanging vertically down over the edge of the table. If g is acceleration due to gravity, the work required to pull the hanging part on to the table is


350) A mass m is attached to the end of a rod of length l. The mass goes around a vertical circular path with the other end hinged at the centre. What should be the minimum velocity of mass at the bottom of the circle, so that the mass complete the circle?


351) A bullet of mass a and velocity b is fired into a large block of mass c. The final velocity of the system is


352) A body of mass 10 kg is moving on a horizontal surface by applying a force of 10 N in forward direction. If
body moves with constant velocity, the work done by force of fiction for a displacement of 2m is


353) A ball dropped from a height of 2m rebounds to a height of 1.5 m after hitting the ground. Then the
percentage of energy lost is


354) Which of the following statements is wrong?


355) Which of the following graphs show variation of potential energy (U) with position x.


356) A rope ladder with a length l carrying a man with a mass m at its end is attached to the basket of balloon
with a mass M. The entire system is in equilibrium in the air. As the man climbs up the ladder into the
balloon, the balloon descends b y a height h. Then the potential energy of the man


357) A particle is projected at 60° to the horizontal with a kinetic energy K. The kinetic energy at the highest
point is


358) Which of the following graphs is correct between kinetic energy (E), potential energy (U) and height (h)
from the ground of the particle


359) A 2 kg block slides on a horizontal floor with a speed of 4 m/s. It strikes a uncompressed spring, and compresses it till the block is motionless. The kinetic friction force is 15 N and spring constant is 10,000 N/m. The spring compresses by


360) Quantity/Quantities remaining constant in a collision is/are


361) A billiards player hits a stationary ball by an identical ball to pocket the target ball in a corner pocket that is at an angle of 35° with respect to the direction of motion of the first ball. Assuming the collision as elastic and that friction and rotational motion are not important, the angle made by the target ball with respect to the incoming ball is


362) A machine which is 75% efficient uses 12 J of energy in lifting up a 1 kg mass through a certain distance. The mass is then allowed to fall through, that distance. The velocity of the ball at the end of its fall is


363) A body of mass M moves with velocity v and collides elastically with a another body of mass m(M>>m) at rest then the velocity of body of mass m is


364) A particle, initially at rest on a frictionless horizontal surface, is acted upon by a horizontal force which is constant in size and direction. A graph is plotted between the work done (W) on the particle, against the speed of the particle, (v). If there are no other horizontal forces acting on the particle the graph would look like


365) A body of mass 50 kg is projected vertically upwards with velocity of 100 m/sec. 5 seconds after this body breaks into 20 kg and 30 kg. If 20 kg piece travels upwards with 150 m/sec, then the velocity of the block will be


366) Two solid rubber balls A and B having masses 200 and 400 g respectively are moving in opposite
directions with velocity of A equal to 0.3m/s. After collision the two balls come to rest, then the velocity of
B is


367) A space craft of mass M and moving with velocity v suddenly breaks in two pieces of same mass m. After
the explosion one of the mass m becomes stationary. What is the velocity of the other part of craft?


368) A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It slides down a smooth
surface to the ground, then climbs up another hill of height 30 m and finally slides down to a horizontal
base at a height of 20 m above the ground. The velocity attained by the ball is


369) Which of the following statements are incorrect?
(i)If there were no friction, Work need to be done to move a body up an inclined plane is zero.(ii)If there were no friction, moving vehicles could not be stopped even by locking the brakes.
(iii)As the angle of inclination is increased, the normal reaction on the body placed on it increases.
(iv)A duster weighing 0.5 kg is pressed against a vertical board with a force of 11 N. If the coefficient of friction is 0.5, the work done in rubbing it upward through a distance of 10 cm is 0.55J.


370) A body of mass 5 kg is placed at the origin, and can move only on the x-axis. A force of 10 N is acting on it in a direction making an angle of 60° with the x-axis and displaces it along the x-axis by 4 metres. The work done by the force is


371) If the unit of force and length each be increased by four times, then the unit of energy is increased by


372) A billiard ball moving with a speed of 5 m/s collides with an identical ball originally at rest. If the first ball stops after collision, then the second ball will move forward with a speed of


373) A body of mass 5 kg is thrown vertically up with a kinetic energy of 490 J. The height at which the kinetic energy of the body becomes half of the original value is


374) A 0.5 kg ball is thrown up with an initial speed 14 m/s and reaches a maximum height of 8.0m. How much energy is dissipated by air drag acting on the ball during the ascent


375) A particle is released from a height s. At certain height its kinetic energy is three times its potential energy. The height and speed of the particle at that instant are respectively


376) A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 ft tall building .After a fall of 30 ft each towards earth ,their respective kinetic energies will be in the ratio of


377) When a spring is stretched by 2 cm, it stores 100 J of energy. If it is stretched further by 2 cm, the stored energy will be increased by


378) A shell of mass m moving with velocity v suddenly breaks into 2 pieces. The part having mass m/4 remains stationary. The velocity of the other shell will be


379) A light and a heavy body have equal kinetic energy. Which one has a greater momentum


380) A bag (mass M) hangs by a long thread and a bullet (mass m) comes horizontally with velocity v and gets caught in the bag. Then for the combined (bag + bullet) system


381) If the linear momentum is increased by 50%, then kinetic energy will be increased by


382) A shell of mass 200 gm is ejected from a gun of mass 4 kg by an explosion that generates 1.05 kg of energy. The initial velocity of the shell is


383) A body of mass m moving with velocity v collides head on another body of mass 2m which is initially at rest. The ratio of KE of colliding body before and after collision body before and after collision will be


384) A block of mass 5kg is resting on a smooth surface. At what angle a force of 20N be acted on the body so that it will acquired a kinetic energy of 40J after moving 4m


385) A long spring, when stretched by x cm has a potential energy U. On increasing the length of spring by stretching to nx cm, the potential energy stored in the spring will be


386) When a force is applied on a moving body, its motion is retarded. Then the work done is


387) If a body of mass 3 kg is dropped from the top of a tower of height 25 m, then its kinetic energy after 3 s will be


388) A spring of force constant 800 N/m has an extension of 5cm. The work done in extending it from 5 cm to 15 cm is


389) A body moving with a velocity v, breaks up into two equal parts. One of the part retraces back with velocity v.Then, the velocity of the other part is


390) Four particles given, have same momentum. Which has maximum kinetic energy


391) In which case does the potential energy decrease


392) A body moves a distance of 10 m along a straight line under action of 5 N force. If work done is 25 J, then
angle between the force and direction of motion of the body will be


393) A body of mass 5 kg moving with a velocity 10 m/s collides with another body of the mass 20 kg at, rest
and comes to rest. The velocity of the second body due to collision is


394) It is easier to draw up a wooden block along an inclined plane than to haul it vertically, principally because


395) A sphere of mass m moving with a constant velocity u hits another stationary sphere of the same mass. If e
is the coefficient of restitution, then the ratio of the velocity of two spheres after collision will be


396) A bullet of mas m moving with velocity v strikes a block of mass M at rest and gets embedded into it. The
kinetic energy of the composite block will be


397) If momentum is increased by 20%, then kinetic energy increases by


398) A particle falls from a height h upon a fixed horizontal plane and rebounds. If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is


399) Statement I Two particles moving in the same direction do not lose all their energy in a completely inelastic collision.
Statement II Principle of conservation of momentum holds true for all kinds of collisions.


400) A ball is dropped from a height h. If the coefficient of restitution be e, then to what height will it rise after jumping twice from the ground


401) A rubber ball is dropped from a height of 5 m on a planet, where the acceleration due to gravity is not known. On bouncing it rises to 1.8 m. The ball loses its velocity on bouncing by a factor of


402) A bullet is fired from a rifle. If the riffle recoils freely, then the kinetic energy of the rifle is


403) In an inelastic collision, what is conserved


404) A ball is dropped from height 20 m. If coefficient of restitution is 0.9, what will be the height attained after first bounce?


405) A particle is moving under the influence of a force given by F=kx where k is a constant and x is the distance moved. The energy (in joules) gained by the particle in moving from x=0 to x=3 is


406) A ball is projected vertically upwards with a certain initial speed. Another ball of the same mass is projected at an angle of 60° with the vertical with the same initial speed. At highest points of their journey, the ratio of their potential energies will be


407) If the K.E. of a body is increased by 300%, its momentum will increase by


408) A ball is projected vertically down with an initial velocity from a height of 20 m onto a horizontal floor. During the impact it loses 50% of its energy and rebounds to the same height. The initial velocity of its projection is


409) Identify the wrong statement


410) If a shell fired from a cannon, explodes in mid air, then


411) A body of mass 2 kg is thrown up vertically with kinetic energy of 490 J. The height at which the kinetic energy of the body becomes half of its original value is?


412) A particle is moving under the influence of a force given by F=kx ,where k is a constant and x is the distance moved. The energy (in joule )gained by the particle in moving from x=0 to x=3 is


413) The kinetic energy acquired by a mass m in travelling a certain distance d starting from rest under the action of a constant force is directly proportional to


414) Statement I In an elastic collision between two bodies, the relative speed of the bodies after collision is equal to the relative speed before the collision.
Statement II Inan elastic collision, the linear momentum of the system is conserved.


415) A ball is released from the top of a tower. The ratio of work done by force of gravity in first, second and third second of the motion of the ball is


416) A smooth sphere of mass M moving with velocity u directly collides elastically with another sphere of mass m at rest. After collision their final velocities are V and v respectively. The value of v is


417) If a force F is applied on a body and it moves with a velocity v, the power will be


418) The work done in pulling up a block of wood weighing 2 kN for a length of 10 m on a smooth plane inclined at an angle of 15° with the horizontal is [sin15°=0.2588]


419) A wire is stretched under a force. If the wire suddenly snaps the temperature of the wire


420) A ball of mass 2kg and another of mass 4kg are dropped together from a 60 feet tall building. After a tall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of


421) The blocks of mass m each are connected to a spring of spring constant k as shown in figure. The maximum displacement in the block is


422) In an elastic collision of two particles the following is conserved


423) A rod AB of mass 10 kg and length 4 m rests on a horizontal floor with end A fixed so as to rotate it in vertical plane about perpendicular axis passing through A. If the work done on the rod is 100 J, the height to which the end B be raised vertically above the floor is


424) Choose the incorrect statement


425) An elastic string of unstretched length L and force constant k is stretched by a small length x. It is further stretched by another small length y. The work done in the second stretching is


426) A ball is dropped from a height h on a floor of coefficient of restitution e.The total distance covered by the ball just before second hit is


427) A bomb of mass 9 kg explodes into two parts. One part of mass 3 kg moves with velocity 16 m/s ,then the KE of the other part is


428) A body of mass ‘M’ collides against a wall with a velocity v and retraces its path with the same speed. The change in momentum is (take initial direction of velocity as positive)


429) A wire of length L suspended vertically from a rigid support is made to suffer extension l in its length by
applying a force F. The work is


430) A man pushes a wall and falls to displace it. He does


431) A spring with spring constant k when stretched through 1 cm the potential energy is U.If it is stretched by
4 cm ,the potential energy will be


432) A particle is released from a height h, At a certain height; its KE is two times its potential energy. Height
and speed of the particle at that instant are


433) A constant power p is applied to a car starting from rest. If v is the velocity of the car at time t, then


434) A space craft of mass ‘M’ and moving with velocity ‘v’ suddenly breaks in two pieces of same mass m. After
the explosion one of the mass ‘m’ becomes stationary. What is the velocity of the other part of craft


435) A body of mass 2 kg is moving with velocity 10 m/s towards east. Another body of same mass and same velocity moving towards north collides with former and coalesces and moves towards north-east. Its velocity is


436) A ball moves in a frictionless inclined table without slipping. The work done by the table surface on the ball is


437) In a head on elastic collision of a very heavy body moving at v with a light body at rest, velocity of heavy body after collision is


438) A particle is dropped from a height h. A constant horizontal velocity is given to the particle. Taking g to be constant every where, kinetic energy E of the particle w.r.t. time t is correctly shown in


439) The slope of the kinetic energy displacement curve of a particle in motion is


440) A quarter horse power motor runs at a speed of 600 r.p.m. Assuming 40% efficiency the work done by the
motor in one rotation will be


441) From an automatic gun a man fires 360 bullet per minute with a speed of 360 km/hour. If each weighs
20 g, the power of the gun is


442) Two bodies of masses 2m and m have their K.E. in the ratio 8: 1, then their ratio of momenta is


443) A particle is released from a height S. At certain height its kinetic energy is three times its potential energy.
The height and speed of the particle at that instant are respectively


444) If velocity of a body is twice of previous velocity, then kinetic energy will become


445) A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power
delivered to it at time t is proportional to


446) For inelastic collision between two spherical rigid bodies


447) A cylinder of mass 10kg is sliding on a plane with an initial velocity of 10 m/s. If coefficient of friction between surface and cylinder is 0.5, then before stopping it will describe


448) A stone is dropped from the top of a tall tower. The ratio of the kinetic energy of the stone at the end of three seconds to the increase in the kinetic energy of the stone during the next three seconds is


449) A body of mass m is at rest. Another body of same mass moving with velocity V makes head on elastic collision with the first body. After collision the first body starts to move with velocity


450) The bob of a simple pendulum (mass m and length l) dropped from a horizontal position strikes a block of the same mass elastically placed on a horizontal frictionless table. The K.E. of the block will be


451) A bullet hits and gets embedded in a solid block resting on a frictionless surface .In this process which one of the following is correct?


452) The height of the dam, in a hydroelectric power station is 10m. In order to generate 1 MW of electric power, the mass of water (in kg/s) that must fall per second on the blades of the turbines


453) In an inelastic collision


454) A ball dropped from a height of 2 m rebounds to a height of 1.5 m after hitting the ground. Then the
percentage of energy lost is


455) A bomb of mass 3.0 kg explodes in air into two pieces of masses 2.0 kg and 1.0 kg. The smaller mass goes
at a speed of 80 m/s. The total energy imparted to the two fragments is


456) An athlete in the Olympic covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in
the range


457) A body of mass m moving with a constant velocity v hits another body of the same mass moving with the
same velocity v but in the opposite direction and sticks to it. The velocity of the compound body after
collision is


458) An engine pumps water continuously through a hole. Speed with which water passes through the hole
nozzle is v and k is the mass per unit length of the water jet as it leaves the nozzle. Find the rate at which
kinetic energy is being imparted to the water


459) Consider a rubber ball freely falling from a height h = 4.9 m onto a horizontal elastic plate. Assume that
the duration of collision is negligible and the collision with the plate is totally elastic.
Then the velocity as a function of time and the height as a function of time will be


460) In an explosion a body breaks up into two pieces of unequal masses. In this


461) A lorry and a car moving with the same K.E. are brought to rest by applying the same retarding force, then


462) For a system to follow the law of conservation of linear momentum during a collision , the condition is
Total external force acting on the system is zero.
Total external force acting on the system finite and time of collision is negligible.
Total internal force acting on the system is zero.


463) A horizontal force of 5N is required to maintain a velocity of 2 m/s for a block of 10 kg mass sliding over a
rough surface. The work done by this force in one minute is


464) Consider the following statements A and B and identify the correct answer
III. In an elastic collision, if a body suffers a head on collision with another of same mass at rest, the first
body comes to rest while the other starts moving with the velocity of the first one
IV. Two bodies of equal mass suffering a head on elastic collision merely exchange their velocities.


465) A pump motor is used to deliver water at a certain rate from s given pipe. To obtain twice as much water
from the same pipe in the same time, power of the motor has to be increased to


466) A force of 5 N moves the particle through a distance of 10 m. If 25 J of work is performed, then the angle
between the force and the direction of motion is


467) A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?


468) A body moving with velocity v has momentum and kinetic energy numerically equal. What is the value of v


469) When a spring is extended by 2 cm energy stored is 100 J. When extended by further 2 cm, the energy increases by


470) Two springs of spring constants 1500 N/m and 3000 N/m respectively are stretched with the same force. They will have potential energy in the ratio


471) A neutron makes a head-on elastic collision with a stationary deuteron. The fractional energy loss of the neutron in the collision is


472) Two bodies of masses 0.1 kg and 0.4 kg move towards each other with the velocities 1 m/s and 0.1 m/s respectively, After collision they stick together. In 10 sec the combined mass travels


473) The kinetic energy of a body is increased by 300%. What is the percentage increase in the momentum of the body?


474) The area of the acceleration-displacement curve of a body gives


475) A neutron travelling with a velocity v and K.E. E collides perfectly elastically head on with the nucleus of an atom of mass number A at rest. The fraction of total energy retained by neutron is


476) A body of mass 2kg makes an elastic collision with another body at rest and continues to move in the original direction with one fourth of its original speed. The mass of the second body which collides with the first body is


477) A running man has half the kinetic energy of that of a boy of half of his mass. The man speeds up by 1m/s so as to have same K.E.. as that of the boy. The original speed of the man will be


478) A long spring is stretched by 2 cm and its potential energy is U. If the spring is stretched by 10 cm; its
potential energy will be


479) Two balls of masses 2 g and 6 g are moving with KE in the ratio of 3:1. What is the ratio of their linear
momenta?


480) A box is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to


481) In elastic collision


482) From a waterfall, water is falling down at the rate of 100 kg/s on the blades of turbine. If the height of the ball is 100 m, then the power delivered to the turbine is approximately equal to


483) A 60 kg man runs up a staircase in 12 seconds while a 50 kg man runs up the same staircase in 11 seconds. The ratio of the rate of doing their work is


484) A body of mass 4 kg moving with velocity 12 m/s collides with another body of mass 6 kg at rest. If two bodies stick together after collision, then the loss of kinetic energy of system is


485) A man starts walking from a point on the surface of earth (assumed smooth) and reaches diagonally opposite point. What is the work done by him


486) A light and a heavy body have equal momenta. Which one has greater K.E.


487) A ball hits the floor and rebounds after inelastic collision. In this case


488) If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate
more before coming to rest


489) Under the action of a force F=Cx, the position of a body changes from 0 to x.The work done is


490) A block of mass m at the end of the string is whirled round a vertical circle of radius r. The critical speed of
the block at the top of the swing is


491) A body of mass m having an initial velocity v, makes head on collision with a stationary body of mass M. After the collision, the body of mass m comes to rest and only the body having mass M moves. This will happen only when


492) A rifle bullet loses 1/20th of its velocity in passing through a plank. The least number of such planks required just to stop the bullet is


493) The diagrams represent the potential energy U of a function of the inter-atomic distance r. Which diagram corresponds to stable molecules found in nature


494) A force of 5 N acts on a 15 kg body initially at rest. The work done by the force during the first second of motion of the body is


495) A body at rest explodes into two equal parts. Then,


496) A particle is released from a height S.At certain height its kinetic energy is three times its potential energy .The height and speed of the particle at that instant are respectively


497) An athlete in the Olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to
be in the range


498) A body projected vertically from the earth reaches a height equal to earth’s radius before returning to the
earth. The power exerted by the gravitational force is greatest


499) A bullet hits and gets embedded in a solid block resting on a horizontal frictionless table. What is
conserved


500) mass of M kg is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of 45° with the initial vertical direction is


501) In the non-relativistic regime, if the momentum, is increased by 100%, the percentage increase in kinetic energy is


502) An ideal spring with spring constant k is hung from the ceiling and a block of mass M is attached to its lower end. The mass is released with the spring initially unstretched. Then the maximum extension in the spring is


503) Two springs A and B are stretched by applying forces of equal magnitudes at the four ends. If spring constant of A is 2 times greater than that of spring B, and the energy stored in A is E, that in B is


504) A spring with spring constant k when stretched through 1 cm, the potential energy is U. If it is stretched by 4 cm. The potential energy will be


505) Two balls at same temperature collide. What is conserved


506) A body moving with velocity v has momentum and kinetic energy numerically equal. What is the value of v?


507) The force constant of a weightless spring is 16 N/m. A body of mass 1.0 kg suspended from it is pulled down through 5 cm and then released. The maximum kinetic energy of the system (spring + body) will be


508) A plate of mass m, length b and breadth a is initially lying on a horizontal floor with length parallel to the floor and breadth perpendicular to the floor. The work done to erect it on its breadth is


509) A 16 kg block moving on a frictionless horizontal surface with a velocity of 4 m/s compresses an ideal spring and comes to rest. If the force constant of the spring be 100 N/m, then the spring is compressed by


510) A nucleus at rest splits into two nuclear parts having same density and radii in the ratio 1:2. Their velocities are in the ratio


511) The power of a water jet flowing through an orifice of radius r with velocity v is


512) If two balls each of mass 0.06 kg moving in opposite directions with speed 4 m/s collide and rebound with the same speed, then the impulse imparted to each ball due to other is


513) A one kilowatt motor is used to pump water from a well 10 m deep. The quantity of water pumped out per
second is nearly


514) The potential energy of a system increases if work is done


515) If a skater of weight 3 kg has initial speed 32 m/s and second one of weight 4 kg has 5 m/s. After collision,
they have speed (couple) 5 m/s. Then the loss in K.E. is


516) The area under the displacement-force curve gives


517) The work done against gravity in taking 10 kg mass at 1m height in 1 sec will be


518) The power of pump, which can pump 200 kg of water to a height of 50 m in 10 sec, will be


519) A ball moving with speed v hits another identical ball at rest. The two balls stick together after collision. If
specific heat of the material of the balls is S, the temperature rise resulting from the collision is


520) According to work-energy theorem, the work done by the net force on a particle is equal to the change in
its


521) A body is moved along a straight line by machine delivering a constant power. The distance moved by the
body in time t is proportional to


522) A ball is dropped from height 10 m. Ball is embedded in sand 1 m and stops, then


523) A 50 kg man with 20 kg load on his head climbs up 20 steps of 0.25m height each. The work done in
climbing is


524) Stopping distance of a moving vehicle is directly proportional to


525) A spring of 40 mm long is stretched by the application of a force. If 10 N force required to stretch the spring through 1 mm, then work done in stretching the spring through 40 mm


526) A ball is allowed to fall from a height of 10 m. If there is 40% loss of energy due to impact, then after one impact ball will go up to


527) A man does a given amount of work in 10 sec. Another man does the same amount of work in 20 sec. The ratio of the output power of first man to the second man is


528) The centripetal acceleration of a particle varies inversely with the square of the radius r of the circular path .The KE of this particle varies directly as


529) A particle of mass ‘m’ and charge ‘q’ is accelerated through a potential difference of ‘V’ volt. Its energy is


530) If F is the force required to keep a train moving at a constant speed v,the power required is


531) Two masses of 1g and 4g are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is


532) Consider the following two statements
1. Linear momentum of a system of particles is zero
2. Kinetic energy of a system of particles is zero,
Then


533) Which of the following is not a perfectly inelastic collision


534) A body is acted upon by a force, which is inversely proportional to the distance covered (x). The work done will be proportional to


535) Which of the following is a scalar quantity


536) A car of mass ‘m’ is driven with acceleration ‘a’ along a straight level road against a constant external resistive force ‘R’. When the velocity of the car is ‘V’, the rate at which the engine of the car is doing work will be


537) An electric immersion heater of 1.08 kW is immersed in water. After the water has reached a temperature of 100℃, how much time will be required to produce 100 g of steam


538) If a shell fired from a cannon ,explodes in mid air, then


539) The height of the dam, in a hydroelectric power station is 10 m. In order to generate 1 MW of electric power,
The mass of water (in kg) that must fall per second on the blades of the turbines is


540) A ball is dropped from a height of 20 cm. Ball rebounds to a height of 10 cm. What is the loss of energy?


541) A person holds a bucket of weight 60 N. He walks 7m along the horizontal path and then climbs up a vertical distance of 5 m. The work done by the man is


542) A vertical spring with force constant k is fixed on a table .A ball of mass m at a height h above the free upper end of the spring falls vertically on the spring, so that the spring is compressed by a distance d. The net work done in the process is


543) A ball of mass m moves with speed v and strikes a wall having infinite mass and it returns with same speed then the work done by the ball on the wall is


544) A bullet of mass m moving with velocity v strikes a suspended wooden block of mass M. If the block rises to a height h, the initial velocity of the block will be


545) A particle P moving with speed v undergoes a head–on elastic collision with another particle Q of identical mass but at rest. After the collision


546) A motor is used to deliver water at a certain rate through a given horizontal pipe. To deliver n-times the water through the same time the power of the motor must be increased as follows


547) The kinetic energy of a body becomes four times its initial value. The new momentum will be


548) An apple gives 21 kJ energy to a boy. How much height he can climb by using this energy if his efficiency is 28% (mass of boy = 40 kg)


549) A sphere collides with another sphere of identical mass. After collision, the two spheres move. The
collision is inelastic. Then the angle between the directions of the two spheres is


550) A ball of mass 10 kg is moving with a velocity of 10 m/s. It strikes another ball of mass 5 kg which is
moving in the same direction with a velocity of 4 m/s. If the collision is elastic , their velocities after the
collision will be, respectively


551) Two identical blocks A and B, each of mass ‘m’ resting on smooth floor are connected by a light spring of
natural length L and spring constant K, with the spring at its natural length. A third identical block ‘C’
(mass m) moving with a speed v along the line joining A and B collides with A. The maximum compression
in the spring is


552) A body moves a distance of 5m along a straight line under the action of a force of 10 N. If the work done is
25 J, then the angel which the force makes with the direction of motion of the body is


553) You lift a heavy book from the floor of the room and keep it in the book–shelf having a height 2 m. In this
process you take 5 seconds. The work done by you will depend upon


554) A body of mass M is dropped from a height h on a sand floor. If the body penetrates x cm into the sand, the
average resistance offered by the sand to the body is


555) The potential energy of a weight less spring compressed by a distance a is proportional to


556) In the stable equilibrium position, a body has


557) A body falling from a height of 10m rebounds from hard floor. If it loses 20% energy in the impact, then coefficient of restitution is


558) Which of the following is a unit of energy


559) A body of mass 0.1 kg moving with a velocity of 10 m/s hits a spring (fixed at the other end) of force constant 1000 N/m and comes to rest after compressing the spring. The compression of the spring is


560) The coefficient of restitution e for a perfectly elastic collision is


561) To the free end of spring hanging from a rigid support, a block of mass m is hung and slowly allowed to come to its equilibrium position. Then stretching in the spring is d. if the same block is attached to the same spring and allowed to fall suddenly, the amount of stretching is (force constant ,k)


562) If a long spring is stretched by 0.02 m, its potential energy is U. If the spring is stretched by 0.1 m, then its
potential energy will be


563) A ball of mass m moving with velocity V, makes a head on elastic collision with a ball of the same mass
moving with velocity 2V towards it. Taking direction of V as positive velocities of the two balls after
collision are


564) The power supplied by a force acting on a particle moving in a straight line is constant. The velocity of the
particle varies with the displacement x as


565) Two masses of 1 g and 4g are moving with equal kinetic energies. The ratio of the magnitudes of their
linear momenta is


566) A particle of mass 100g is thrown vertically upwards with a speed of 5m/s. The work done by the force of
gravity during the time the particle goes up is


567) The potential energy of a certain spring when stretched through a distance s is 10 J .The amount of work
done (in joule)that must be done on this spring to stretch it through an additional distance s, will be


568) A body moves a distance of 10 m along a straight line under the action of a force of 5 N. If the work done is
25 joules, the angle which the force makes with the direction of motion of the body is


569) A body of mass m is rest. Another body of same mass moving with velocity v makes head on elastic
collision with the first body. After collision the first body starts to moves with velocity


570) A mass of 20 kg moving with a speed of 10 m/s collides with another stationary mass of 5 kg As a result of the collision, the two masses stick together. The kinetic energy of the composite mass will be


571) A body of mass m kg is lifted by a man to a height of one metre in 30 sec. Another man lifts the same mass to the same height in 60 sec. The work done by them are in the ratio


572) The kinetic energy acquired by a body of mass m in travelling some distance s, starting from rest under the action of a constant force, is directly proportional to


573) Which of the following is not a conservative force


574) A chain of mass M is placed on a smooth table with 1/3 of its length L hanging over the edge. The work done in pulling the chain back to the table is


575) A motor drives a body along a straight line with a constant force. The power P developed by the motor
must vary with time t as shown in figure


576) A uniform chain of length 2m is kept on a table such that a length of 60 cm hangs freely from the edge of
the table. The total mass of the chain is 4kg. What is the work done in pulling the entire chain on the table


577) Which among the following, is a form of energy


578) If the momentum of a body is increased by 100%, then the percentage increase in the kinetic energy is


579) A rod AB of mass 10kg and length 4m rests on a horizontal floor with end A fixed so as to rotate it in
vertical plane about perpendicular axis passing through A. If the work done on the rod is 100 J, the height
to which the end B be raised vertically above the floor is


580) A particle of mass m moving eastward with a speed v collides with another particle of the same mass
moving northward with the same speed v. The two particles coalesce on collision. The new particle of
mass 2m will move in the north-easterly direction with a velocity


581) A ball hits a vertical wall horizontally at 10 m/s bounces back at 10 m/s


582) Two bodies moving towards each other collide and move away in opposite directions. There is some rise
in temperature of bodies because a part of the kinetic energy is converted into


583) A lead ball strikes a wall and falls down, a tennis ball having the same mass and velocity strikes the wall
and bounces back. Check the correct statement


584) A bomb of mass 9 kg explodes into 2 pieces of mass 3kg and 6kg. The velocity of mass 3kg is 1.6 m/s, the
K.E. of mass 6kg is


585) If force and displacement of particle in direction of force are doubled. Work would be


586) A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic
energy for any displacement x is proportional to


587) If the kinetic energy of a body increases by 0.1%, the percent increase of its momentum will be


588) The slope of the kinetic energy versus position vector gives the rate of change of


589) A spring gun of spring constant 90 N/cm is compressed 12 cm by a ball of mass 16 g. If the trigger is
pulled, the velocity of the ball is


590) A block of mass 10 kg slides down a rough slope which is inclined at 45° to the horizontal. The coefficient
of sliding friction is 0.30. When the block has slide 5 m, the work done on the block by the force of friction
is nearly


591) A car of mass m is driven with an acceleration a along a straight level road against a constant external
resistive force R. When the velocity of the car is v, the rate at which engine of the car is doing work, will be


592) An open knife edge of mass ‘m’ is dropped from a height ‘h’ on a wooden floor. If the blade penetrates upto
the depth ‘d’ into the wood, the average resistance offered by the wood edge is


593) A bomb of mass 3m kg explodes into two pieces of mass m kg and 2m kg. If the velocity of m kg mass is
16 m/s, the total kinetic energy released in the explosion is


594) A body at rest breaks up into 3 parts. If 2 parts having equal masses fly off perpendicularly each after with
a velocity of 12 m/s, then the velocity of the third part which has 3 times mass of each part is


595) A dam is situated at a height of 550 m above sea level and supplies water to a power house which is at a
height of 50 m above sea level. 2000 kg of water passes through the turbines per second. What would be
the maximum electrical power output of the power house if the whole system were 80% efficient?


596) A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of
the particle, the motion of the particle takes place in a plane. It follows that


597) A spring when stretched by 2 mm its potential energy becomes 4 J. If it is stretched by 10 mm, its potential
energy is equal to


598) A ball whose kinetic energy is E, is projected at an angle 45° to the horizontal. The kinetic energy of the
ball at the highest point of its flight will be


599) A body of mass 10 kg at rest is acted upon simultaneously by two forces 4 N and 3 N at right angles to
each other. The kinetic energy of the body at the end of 10 sec is


600) If the K.E. of a particle is doubled, then its momentum will


601) When a body moves with some friction on a surface


602) An ice cream has a marked value of 700 kcal. How many kilowatt - hour of energy will it deliver to the body as it is digested


603) Two bodies with kinetic energies in the ratio of 4∶1 are moving with equal linear momentum. The ratio of their masses is


604) If a man increase his speed by 2 m/s, his K.E. is doubled, the original speed of the man is


605) The momentum of a body increases by 20%. The percentage increase in its kinetic energy is


606) A big ball of mass M, moving with velocity u strikes a small ball of mass m, which is at rest. Finally small ball obtains velocity u and big ball v. Then what is the value of v


607) In which of the following cases, can the work done increase the potential energy?


608) A rock of mass m is dropped to the ground from a height h. A second rock with mass 2m is dropped from the same height. When second rock strikes the ground, what is its kinetic energy?


609) A bomb of 12 kg divides in two parts whose ratio of masses is 1∶3. If kinetic energy of smaller part is 216 J, then momentum of bigger part in kg-m/sec will be


610) An elastic ball is dropped from a height h and it rebounds many times from the floor .If the coefficient of restitution is e, the times interval between the second and the third impact, is


611) A body is moving with velocity v, breaks up into two equal parts. One of the part retraces back with velocity v. Then the velocity of the other part is


612) The energy associated with one gram of mass is


613) Identify the false statement from the following


614) A shell initially at rest explodes into two pieces of equal mass, then the two pieces will


615) The quantity that is not conserved in an inelastic collision is


616) Two masses of 1 g and 4 g have same kinetic energy what is the ratio of their momenta?


617) A car of mass 1250 kg is moving at 30 m/s. Its engine delivers 30 kW while resistive force due to surface is 750 N. What max acceleration can be given in the car


618) At high altitude, a body explodes at rest into two equal fragments with one fragment receiving horizontal velocity of 10 m/s. Time taken by the two radius vectors connecting point of explosion to fragments to make 90° is


619) A particle of mass m is being circulated on a vertical circle of radius r. If the speed of particle at the highest
point be v, then


620) A particle is placed at the origin and force F = kx is acting on it (where k is positive constant ).if u(0) =
0.the graph u(x) versus x will (where u is potential energy function)


621) A time t=0 s Particle starts moving along the x-axis. If its kinetic energy increases uniformly with time t,
the net force acting on it must be proportional to


622) A stone tied to a string of length L is whirled in a vertical circle with the other end of the string at the
centre. At a certain instant of time, the stone is at its lowest position and has a speed u. The magnitude of
the change in its velocity as it reaches a position where the string is horizontal is


623) A sphere of mass m, moving with velocity V, enters a hanging bag of sand and stops. If the mass of the bag is M and it is raised by height h, then the velocity of the sphere was


624) A particle of mass m moving with velocity v strikes a stationary particle of mass 2m and sticks to it. The speed of the system will be


625) The kinetic energy of a body of mass 3kg and momentum 2 Ns is


626) A particle of mass m at rest is acted upon by a force F for a time t. Its kinetic energy after an interval t is


627) A body of mass M is hung by a long thread and a bullet of mass m hits it horizontally with a velocity v and gets embedded in the body. Then for the body and the bullet system


628) The spring extends by x on loading, then energy stored by the spring is :
(If T is the tension in spring and k is spring constant)


629) A particle of mass M starting from rest undergoes uniform acceleration. If the speed acquired in time T is V, the power delivered to the particle is


630) A mass of 0.5 kg moving with a speed of 1.5 m/s on a horizontal smooth surface, collides with a nearly weightless spring of force constant k=50 N/m. The maximum compression of the spring would be


631) A car of mass 1000 kg accelerates uniformly from rest to a velocity of 54 km/hour in 5s. The average power of the engine during this period in watts is (neglect friction)


632) A ball is released from the top of a tower. The ratio of work done by force of gravity in first, Second and
third second of the motion of the ball is


633) A uniform force of 4 N acts on a body of mass 10 kg for a distance of 2.0 m. The kinetic energy acquired by
the body is


634) A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth
surface to the ground, then climbs up another hill of height 30 m and height of 20 m above the ground. The
velocity attained by the ball is


635) A glass ball is dropped from height 10 m. If there is 20% loss of energy due to impact, then after one
impact, the ball will be upto