Calculate the acceleration of the block and trolly system shown in the figure. The coefficient of kinetic friction between the trolly and the surface is 0.05.
( mass of the string is negligible and no other friction exists ).
A car of mass m is moving on a level circular track of radius R. If represents the static friction between the road and tyres of the car, the maximum speed of the car in circular motion is given by -
A conveyor belt is moving at a constant speed of 2 m/s. A box is gently dropped on it. The coefficient of friction between them is µ = 0.5. The distance that the box will move relative to the belt before coming to rest on it, taking g = 10 ms–2 is:
1. 0.4 m
2. 1.2 m
3. 0.6 m
A small mass attached to a string rotates on a frictionless table top as shown. If the tension in the string is increased by pulling the string causing the radius of the circular motion to decrease by a factor of 2, the kinetic energy of the mass will
1. decrease by a factor of 2
2. remain constant
3. increase by a factor of 2
4. increase by a factor of 4
A point mass 'm' is moved in a vertical circle of radius 'r' with the help of a string. The velocity of the mass is at the lowest point. The tension in the string at the lowest point is:
Two masses as shown are suspended from a massless pulley. Calculate the acceleration of the system when masses are left free.
A body of mass 3 kg hits a wall at an angle of 60º & returns at the same angle. The impact time was 0.2 s. Calculate the force exerted on the wall.
1. 150 N
2. 50 N
3. 100 N
4. 75 N
A mass of 1 kg is thrown up with a velocity of 100 m/s. After 5 seconds, it explodes into two parts. One part of mass 400 g comes down with a velocity of 25 m/s. Calculate the velocity of the other part.
1. 40 m/s upward
2. 40 m/s downward
3. 100 m/s upward
4. 60 m/s downward
A mass is performing a vertical circular motion. (see figure) If the average velocity of the particle is increased, then at which point the string will break ?
If force F = 500 – 100t, then function of impulse with time will be :
1. 500t – 50
2. 50t – 10
3. 50 –