Question

Give some examples where work done is zero.

Answer 1

A work is said to be done when a force causes a displacement in its direction. For the work to be done, the following two conditions must be satisfied:

1. A force must be applied.
2. The body should move in the direction in which force is applied.

Situations, where work is not done, are:

1. A table on a floor experiences no work done on it.
2. If we hold a book for some time, there is no work done on it by us.
3. In one rotation of the earth around the sun the work done on the earth by the gravitational force is zero.
4. When we push the wall, there is no movement in the wall, hence no work is done.