Tennis ball example question

p(i) = mu

p(i) = .9 x 30

p(i) = 27 kg ms-1

p(f) = mv

p(f) = .9 x 25

p(f) = 22.5 kg ms-1

^p = p(f) - p(i)

^p = 22.5 kg ms-1 - (-27 kgms-1)

^p = 22.5 kg ms-1 + 27 kg ms-1

^p = 49.5 kg ms-1

A tennis ball with a mass of 900 grams is hit at a velocity of 30 ms-1 towards a wall. It hits the wall perpendicuary and rebounds with a velocity of 25 ms-1.

A, Find the initial momentum of the tennis ball.

m = .9 kg

u = 30 ms-1

p(i) = ?

 

 

B, Find the final momentum of the tennis ball.

m = .9 kg

v = 25 ms-1

p(f) = ?

 

C, Find the change in momentum of the tennis ball.