When does a force is said to be in work ?

When does a force do work ?

Work is said to be done when :

The work done by a force is said to be …….when the applied force does not produce displacement.

Define work. When is work said to be done by a force ?

(a) When does a force do work ? (b) State two examples when a force acting on a body does not do any work. (c) State the mathematical expression of work. (d) Name the SI unit of work.