Physics Past Questions and Answers

I. Its velocity is constant
II. No work is done on the body
III. It has constant acceleration directed away from the centre
IV. The centripetal force is directed towards the centre
Which combination of the above is true of a body moving with constant speed in a circular track?

The velocity ratio of a machine is 5 and its efficiency is 75%. What effort would be needed to lift a load of 150N with the machine?

At a fixed point below a liquid surface, the pressure downwards is P1 and pressure upwards is P2. It can be deduced that

If the force and the velocity on a system are each reduced simultaneously by half, the power of the system is

A catapult used to hold a stone of mass 500g is extended by 20cm with an applied force F. If the stone leaves with a velocity of 40m/s, the value of F is