Question

State the law of conversion of momentum why is a person hit harder when he falls on a hard surface than he falls on sand of the same height

Answer 1

A person hit harder when he falls on a concrete floor than when he falls on a heap of sand from the same height because on a hard surface he is brought to rest in a very short time, so greater force comes into action and he is hit harder. On the other hand, on a heap of sand, he is brought to rest in a longer time and so lesser force is called into play and he is hit slower.

It is based on the law of conservation of momentum that states that the sum of momenta of two objects before collision is equal to sum of momenta after the collision provided there is no external unbalanced force acting on them.