1. 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 J, the

angle which the force makes with the direction of motion of the body is
(a) 00 (b) 300 (c) 600 (d) 900
2. A body of mass m kg is lifted by a man to a height of h m in 30 s. Another man lifts the same mass to the same height
in 60 s. The work done by them are in the ratio
(a) 1 : 2 (b) 1 : 1 (c) 2 : 1 (d) 4 : 1
3. If the KE of a body is increased by 300%, its momentum will increase by
(a) 100% (c) √300% (d) 175%
(b) 150%
4. If the linear momentum is increased by 50%, the KE will increase by
(a) 50% (b) 100% (c) 125% (d) 25%
5. Two bodies with kinetic energies in the ratio 4 : 1 are moving with equal linear momentum. The ratio of their masses
is
(a) 1 : 2 (b) 1 : 1 (c) 4 : 1 (d) 1 : 4
6. A bullet is fired from a rifle. If the rifle recoils freely, then the kinetic energy of rifle is
(a) less than that of the bullet (c) same as that of the bullet
(b) more than that of the bullet (d) equal or less than that of the bullet
7. A steel ball of mass 5g is thrown downward with velocity 10 m/s from height 19.5 m. It penetrates sand by 50 cm.
The change in mechanical energy will be (g = 10 m/s2)
(a) 1 J (b) 1.25 J (c) 1.5 J (d) 1.75 J
8. For inelastic collision between two spherical rigid bodies
(a) the total kinetic energy is conserved (c) the linear momentum is not conserved
(b) the total mechanical energy is not conserved (d) the linear momentum is conserved
9. 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
(a) x2 (b) ex (c) x (d) loge x
10. 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
(a) heat energy (c) nuclear energy
(b) electrical energy (d) mechanical energy

11. A mass of M kg is suspended by a weightless string. The horizontal force that is required to displace it unit the string
makes an angle of 450 with the initial vertical direction is
(a) Mg(√2 + 1) (b) Mg√2 (c) Mg/√2 (d) Mg(√2 – 1)
12. A particle of mass 100 g is thrown vertically upwards with a speed of 5 m/s. The work done by the force of gravity
during the time the particle goes up is
(a) – 0.5 J (b) – 1.25 J (c) 1.25 J (d) 0.5 J
13. A bomb of mass 3.0 kg explodes in air into 2 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
(a) 1.07 kJ (b) 2.14 kJ (c) 2.4 kJ (d) 4.8 kJ
x4 x2
14. The potential energy of a 1 kg particle free to move along the x-axis is given by V(x) = ( 4 − 2 ) J. The total
mechanical energy of the particle is 2 J. Then, the maximum speed (in m/s) is
(a) 3/√2 (b) √2 (c) 1/√2 (d) 2
15. A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 m tall building. After a fall of 30 m each
towards earth, their respective kinetic energies will be in the ratio of
(a) √2 : 1 (b) 1 : 4 (c) 1 : 2 (d) 1 : √2
16. 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 (Take g = 10 m/s2)
(a) 10 m/s (b) 10√30 m/s (c) 40 m/s
(d) 20 m/s
17. A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration ac is varying
with time t as ac = k2rt2, where k is a constant. The power delivered to the particle by the force acting on it is
(a) 2πmk2r2 (b) mk2r2t (c) (mk4r2t5)/3 (d) zero
18. A stone tied to a string of length L is whirled in a vertical circle with the other end of the string at the center. 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
(a) √u2 − 2gL (b) √2gL (c) √u2 − gL (d) √2(u2 − gL)
19. A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg. The velocity of 18 kg mass is 6 m/s.
The KE of the other mass is
(a) 256 J (b) 486 J (c) 524 J (d) 324 J
20. The block of mass M moving on the frictionless horizontal surface collides with the spring of spring constant k and
compresses it by length l. The maximum momentum of the block after collision is
(a) zero (c) √Mk l
(b) Ml2/k (d) kl2/2M M

21. Four smooth steel balls of equal mass at rest are free to move along a straight line without friction. The first ball is
given a velocity of 0.4 m/s. It collides head on with the second ball elastically, the second one similarly, with the third
and so on. The velocity of last ball is
(a) 0.4 m/s (b) 0.2 m/s (c) 0.1 m/s (d) 0.05 m/s
22. A particle of mass m moving with velocity v strikes a stationary particle of mass 2 m and sticks to it. The speed of the
system will be
(a) v/2 (b) 2v (c) v/3 (d) 3v
23. A ball is dropped from height 20 m. If coefficient of restitution is 0.9, what will be the height attained after first
bounce?
(a) 1.62 m (b) 16.2 m (c) 18 m (d) 14 m
24. Which of the following is not an example of perfectly inelastic collision?
(a) A bullet fired into a block, if bullet gets embedded into block
(b) Capture of an electron by an atom (c) A man jumping onto a moving boat
(d) A ball bearing striking another ball bearing
25. A bullet of mass M hits a block of mass M’. The transfer of energy is maximum, when
(a) M’ = M (b) M’ = 2M (c) M’ << M (d) M’ >> M
26. A bullet of mass 50 g is fired from a gun of mass 2 kg. If the total kinetic energy produced is 2050 J, the kinetic energy
of the bullet and the gun respectively, are
(a) 200 J, 5 J (b) 2000 J, 50 J (c) 5 J, 200 J (d) 50 J, 2000 J
27. A metal ball falls from a height of 32 m on a steel plate. If the coefficient of restitution is 0.5, to what height will the
ball rise after second bounce?
(a) 2 m (b) 4 m (c) 8 m (d) 16 m
28. 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
1+e2 1−e2 h 1+e2 h 1−e2
(a) h [ 2] (b) h [ 2] (c) [ 2] (d) [ 2]
1−e 1+e 2 1−e 2 1+e
29. A chain is held on a frictionless table with one-third of its length hanging over the edge. If the chain has a length L
and mass M, how much work is required to pull the hanging part back on the table?
1 1 1
(a) MgL (b) 3 MgL (c) 9 MgL (d) 18 MgL
30. A train of mass 100 ton is being drawn up an incline rising 1 in 49 at the rate of 36 km/h by its engine. If the
resistance due to friction be 1 N/tonne mass of train, then calculate the power of the engine. Given that g = 9.8 m/s2.
(a) 100 W (b) 50 kW (c) 201 kW (d) 20 kW
31. A ball of kinetic energy E is projected at an angle of 450 to the horizontal. The kinetic energy of the ball at the highest
point of its flight will be
(a) E (b) E/√2 (c) E/2
(d) zero
32. A ball is moved along a straight line by a machine delivering constant power. The distance moved by the body in time
t is proportional to
(a) t1/2 (b) t3/4 (c) t3/2 (d) t2
33. A mass of 100 g moving with a velocity of 1 m/s strikes a pendulum bob of mass 100 g. The two masses stick
together. The maximum height reached by the system now is (Take g = 10 m/s2)
(a) zero (b) 5 cm (c) 2.5 cm (d) 1.25 cm