When a body is falling freely from some height, work done by gravity is ____.

When brakes are applied on a moving vehicle, work done by the breaking force is ____.

1 joule = _____ erg

An agent is moving positively charge body towards another fixed positive charge. The work done by the agent is _____.

A man pushes a rigid fixed body and fails to displace it he does

No work is done if

In which of the following work is being not done? 

The kinetic energy of a body will become eight times if 

In case of negative work the angle between the force and displacement is

The rate of doing work is called _____.