(a) A body of mass 5.5 kg is dropped from the 2nd floor of a building which is at a height of 15 m. What is the force acting on it during its fall? (g = 10 ms^-2)

(b) What are isobars ?

(c) How many pulleys are there in a movable block and tackle system with velocity ratio 5 ?

(a) Give one example of pure rotational motion.

(b) Comment on the movement of particles on the axis of rotation in pure rotational motion.

(a) A brass ball is hanging from a stiff cotton thread. Draw a neat labelled diagram showing the forces acting on the brass ball and cotton thread.

(b) Can the couple acting on a rigid body produce translatory motion?

Is it possible that an object is in the state of accelerated motion due to external force acting on it, but no work is being done by the force? Explain it with an example.