For a body to be in equilibrium, which of the following conditions is necessary?

1. Its momentum is zero.
2. Its kinetic energy is zero.
3. Its velocity is zero.
4. lts acceleration is zero.

State the condition when on applying a force, a body has:

(a) translational motion

(b) rotational motion.

Write the expression for the moment of force about a given axis.

State one way to reduce the moment of a given force about a given axis of rotation.