A string of negligible mass going over a clamped pulley of mass m supports a block of mass M as shown in the figure. The force on the pulley by the clamp is given by:
1. √2Mg
2. √2mg
3. g√(M+m)2+m2
4. g√(M+m)2+M2
A pulley fixed to the ceilling carries a string with blocks of mass m and 3 m attached to its ends. The masses of string and pulley are negligible. When the system is released, its centre of mass moves with what acceleration
1. 0
2. g/4
3. g/2
4. –g/2
A block B is placed on top of block A. The mass of block B is less than the mass of block A. Friction exists between the blocks, whereas the ground on which block A is placed is assumed to be smooth. A horizontal force F, increasing linearly with time begins to act on B. The acceleration aA and aB of blocks A and B respectively are plotted against t. The correctly plotted graph is:
1. | 2. | ||
3. | 4. |
The force-time (F – t) curve of a particle executing linear motion is as shown in the figure. The momentum acquired by the particle in time interval from zero to 8 second will be
1. – 2 N-s
2. + 4 N-s
3. 6 N-s
4. Zero
A body of 2 kg has an initial speed 5ms–1. A force acts on it for some time in the direction of motion. The force time graph is shown in figure. The final speed of the body.
1. 9.25 ms–1
2. 5 ms–1
3. 14.25 ms–1
4. 4.25 ms–1
A particle of mass m, initially at rest, is acted upon by a variable force F for a brief interval of time T. It begins to move with a velocity u after the force stops acting. F is shown in the graph as a function of time. The curve is an ellipse.
1. u=πF202m
2. u=πT28m
3. u=πF0T4m
4. u=F0T2m
A body of mass 3kg is acted upon by a force which varies as shown in the graph below. The momentum acquired is given by
1. Zero
2. 5 N-s
3. 30 N-s
4. 50 N-s
The variation of momentum with the time of one of the bodies in a two-body collision is shown in fig. The instantaneous force is the maximum corresponding to the point:
1. P
2. Q
3. R
4. S
Figures I, II, III and IV depict variation of force with time.
(I) | |
(II) | |
(III) | |
(IV) |
The impulse is highest in the case of situations depicted. Figure
1. I and II
2. III and I
3. III and IV
4. IV only
The masses of 10 kg and 20 kg respectively are connected by a massless spring as shown in figure. A force of 200 N acts on the 20 kg mass. At the instant shown, the 10 kg mass has acceleration 12 m/sec2. What is the acceleration of 20 kg mass?
1. 12 m/sec2
2. 4 m/sec2
3. 10 m/sec2
4. Zero