Question

A tennis ball of mass m = 0.08 kg and speed v=29 ms strikes a wall at a 45∘ angle and rebounds with the same speed at 45∘. What is the magnitude of the impulse given to the ball? Express your answer to two significant figures and include the appropriate units.

Answer 1

3.3 kg-m/s

Step-by-step explanation:

The mass of the ball m = 0.08 kg

speed
`v_(1)` = 29 m/s

angle oat which its strikes the wall = 45°

Final speed of rebound
`v_(2)` = 29 m/s

angle of rebound = 45°

Momentum before collision
`p_(1)` = m
`v_(1)` cos ∅

==> 0.08 x 29 cos 45 = 1.64 kg-m/s

since the same variables are maintained in the rebound, then the momentum of rebound will be of the same magnitude, but in the opposite direction

`p_(2)` = -1.64 kg-m/s

The impulse is the change of momentum
`I` =
`p_(1)` -
`p_(2)`

`I` = 1.64 - (-1.64 ) = 1.64 + 1.64 = 3.3 kg-m/s