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n balls each of mass m impinge elastical...

n balls each of mass m impinge elastically each second on a surface with velocity u. The average force experienced by the surface will be

A

mnu

B

2 mnu

C

4 mnu

D

`(1)/(2)` mnu

Text Solution

Verified by Experts

The correct Answer is:
B
Force `(vec(F)) = (d vec(p))/(dt)` = Rate of change of momentum .
As balls collide elastically
Rate of change of momentum `= n[mu - (-mu)]`
` = 2nmu`
`F = 2nmu`
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