A ball of the mass m is moving with velocity v. It strikes the floor and rebounce with the same velocity. If n such balls strike the floor per sec, then force exerted by the balls on the floor is :

Foundation

Physics Foundation

Force and Newtons Law of Motion

Impulse and Momentum

Question

A ball of the mass m is moving with velocity v. It strikes the floor and rebounce with the same velocity. If n such balls strike the floor per sec, then force exerted by the balls on the floor is :

mnv

$\frac{mn}{v}$

2mnv

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100 Change in momentum of ball is,
Δp = –mv – mv = –2mv
Change in momentum of floor,
Δp = 2mv

So, force exerted by one ball per second.
will be F = $\frac{ΔP}{Δt}$ = 2mv.
If n ball strike per second than force exerted by balls on floor will be = 2mnv.