Question

Water sprinkler used for grass lawns begins to rotate as soon as the water is supplied. Explain the principle on which it works.

Answer 1

Newton's third law of motion:

1. Newton’s third law of motion states that when one body exerts a force on the other body, the first body experiences a force which is equal in magnitude in the opposite direction of the force which is exerted.
2. As the water comes out of the sprinkler, it exerts an equal and opposite force on the sprinkler.

Hence, the sprinkler starts rotating.