Physics Past Questions and Answers

When a ship sails from salt water into fresh water, the fraction of its volume above the water surface will

I. Its velocity is constant<br/>II. No work is done on the body<br/>III. It has constant acceleration directed away from the centre<br/>IV. The centripetal force is directed towards the centre<br/>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