Question

What do you mean by work. Give an example of negative work done. What is work to be done to create the velocity from 18km/hr to 19km/hr if the mass of the case is 200kg

Answer 1

whenever of a force acts on the body and the body cover up to setting distance that work is said to be done .

Answer 2

Hence work done is negative. (i) When a body is made to slide over a rough surface, the work done by frictional force is negative. (ii) When brakes are applied on a moving vehicle, the work done by the breaking force is negative.