Now get the best preparation questions and solutions for jee mains and Advanced by Jeemain.guru, Law of motion physics
1. Which of the following cases the net force acting on the body is not zero?
(a) A drop of rain falling down with a constant speed
(b) A cork of mass 10 g floating on the surface of water
(c) A car moving with a constant speed of on a
Rough road
(d) A pebble of mass 0.05 kg is thrown vertically upwards
2. Which one of the following statements is not true about Newton’s second law of motion?
(a) The second law of motion is consistent with the first law
(b) The second law of motion is a vector law
(c) The second law of motion is applicable to a single point
particle
(d) The second law of motion is not a local law
3. A rocket is going upwards with accelerated motion. A man sitting in it feels his weight increased 5 times his own weight. It the mass of the rocket including that of the the man is , how much force is being applied by rocket engine? (Take g =
)
(a) (b)
(c) (d)
4. A trolley of mass 20 kg is attached to a block of mass 4 kg by a massless string passing over a frictionless pulley as shown in the figure. If the coefficient of kinetic friction between trolley and the surface is 0.02, then the acceleration of the trolley and block system is (Take ) :
(a) (b)
(c) (d)
5. A person of mass 50 kg stands on a weighing scale on a lift. If the lift is ascending upwards with a uniform acceleration of , what would be the reading of the weighing scale? (Take
)
(a) 50 kg (b) 60 kg (c) 95 kg (d) 100 kg
6. A body of mass 2 kg is hung on a spring balance mounted vertically in a lift. If the lift descends with an acceleration equal to the acceleration due to gravity ‘g’, the reading on the spring balance will be
(a) 2 kg (b) (4 ×g) kg (c) (2 ×g) kg (d) Zero
7. Two blocks are connected by a string as shown in the diagram. The upper block is hung by another string. A force F applied on the upper string produces an acceleration of in the upward direction in both the blocks. If T and
be the tensions in the two parts of the string, then
(a) and
(b) and
(c) and
(d) and
8. A block of mass 50 kg slides over a horizontal distance of 1 m. If the coefficient of friction between their surfaces is 0.2, then work done against friction is
(a) 98 J (b) 72J (c) 56 J (d) 34 J
9. The magnitude of force (in N) acting on a body varies with time t (in N) as shown. AB, BC and CD are straight line segments. The magnitude of total impulse of force on the body from t = 4 μs to t = 16 μs is
(a) 6 × 10-3Ns (b) 3 × 10-3Ns
(c) 5 × 10-3Ns (d) 6 × 10-3Ns
10. Three blocks of masses m1, m2 and m3 are placed on a horizontal frictionless surface. A force of 40 N pulls the system then calculate the value of T, if m1 = 10kg, m2 = 6 kg, m3 = 4 kg –
(a) 40 N (b) 20 N (c) 10 N (d) 5 N
11. A block is kept on a smooth inclined plane of angle of inclination 30º that moves with a constant acceleration so that the block does not slide relative to the inclined plane. Let F1 be the contact force between the block and the plane. Now the inclined plane stops and let F2 be the contact force between the two in this case. Then F1/F2 is :
(a) 1 (b)
(c) 2 (d)
12. A block of mass ‘m’ is slipping down a rough inclined plane with constant speed. The force on block by plane is –
(a) mg
(b)
(c) Depends upon coefficient of friction
(d) Depends upon angle of inclination
13. A bullet fired into a wooden block, loses half of its velocity after penetrating 90 cm. Before coming to rest it penetrates a further distance of –
(a) 10 cm (b) 20 cm (c) 30 cm (d) 60 cm
14. A trolley T (mass 5 kg) on a horizontal smooth surface is pulled by a load L (2 kg) through a uniform rope ABC of length 2 m and mass 1 kg. As the load falls from BC = 0 to BC = 2m, its acceleration (in m s-2) changes from –
(Take g = 10 m s-2)
(a) 20/6 to 20/5 (b) 20/8 to 30/ 8
(c) 20/5 to 30/ 6 (d) none of these
Get softcopy downloadable pdf of skm sir, JH sir,DB sir, Anna sir only 399rsLATEST POSTS:
- Get Help Writing a Paper for College: 10 Tips From Experts
- Is It Possible to Write Papers Fast with High Quality?
- Step-by-step Guide for Helping Your Child with Homework Assignments.
- 10 Effective Essay Tips for Scholarships
- Motor Vehicle Report