Question

When a body falls, its momentum increases. Does this mean that the momentum is not conserved?

Answer 1

See below.

Explanation:

Note that calling `p = m v` then `(dp)/(dt)=f` or

the momentum variation equals the sum of external actuating forces. If a body is falling under gravity then `f = m g`

Answer 2

What do you mean by 'fall'? I assume it is force. Under the action of force the body as soon as it collides does lose momentum, but the other body gains it.

Explanation:

Conservation of momentum states that linear momentum of a SYSTEM is conserved, not it's particle. When two objects collide because of any reason the total momentum of the system is conserved. So, if we take earth and falling object example, earth and falling object form a system. Hence momentum lost by body is equal to momentum gained by Earth.