Question
Define the term work. State the conditions that need to be satisfied for work to be done. Give some situations in which work is done.
Solution
Work is the amount of force exerted on a body such that it moves in the direction of the force.
Two conditions need to be satisfied for work to be done are as follows:
Two conditions need to be satisfied for work to be done are as follows:
(i) A force should act on the body.
(ii) The body must be displaced in the direction of the applied force.
Work is not done, if either of the above two conditions is not satisfied.
Let consider some examples from the daily life.
(i) Push a pebble lying on a surface. The pebble moves through some distance. Here we apply a force on the pebble and the pebble gets displaced. So, we have done work on the pebble.
(ii) We apply a force to lift a book through a height. The book rises up. We have done work in moving up the book.
(iii) A bullock is pulling a cart. The cart moves. There is a force on the cart and the cart has moved. The bullock has done work on the cart.
