A body is acted upon by two unequal forces in opposite directions, but not in the same line. The effect is that:

1. the body will only have rotational motion
2. the body will only have translational motion
3. the body will have neither rotational motion nor translational motion
4. the body will have rotational as well as translational motion.

Out of the following which one is an example of dynamic equilibrium ?

(1) Moon revolving around the earth
(2) A pebble fixed at the end of a string whirling in a circular path
(3) An aeroplane moving at a constant height
(4) A beam balance balanced in a horizontal position.

1. (3) and (4)
2. (1), (2) and (3)
3. (1) and (2)
4. (1) and (3)

State whether the moment of force is a scalar or vector quantity?

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