Question

2.) Roger throws a tennis ball at a wall. The tennis ball has a mass of 0.6 kg and a velocity of 25 m/s before striking the wall. After striking the wall, the tennis ball has a velocity of 20 m/s. The ball is in contact with the wall for 0.1 secs. a.) What is the change in momentum of the ball after striking the wall? b.) With what force did the ball strike the wall?

Answer 1

A)

As we know that change in momentum is given by

AP = m(uf -vi)

Where vf is the final velocity abd vi is the initial velocity

$\triangle P=0.6\times (20-25)$

$\triangle P=-3 Kg m/s$

Here minus sign signifies that final momentum is less than initial momentum.

B) as we know that force exerted on the wall will be

$F=|\frac{\triangle P}{t} |$

$F=|\frac{-3}{0.1}|$

$F=30N$