Question

A ball is thrown at a wall with a velocity of 5 m/s and bounces off at 4 m/s as shown in the diagram. If the impulse provided by the wall is 3 Nm, then what is the mass of the ball?

Answer 1

Answer:

m = 3 kg

Explanation:

It is given that,

Initial speed of a ball is 5 m/s, u = 5 m/s

Final speed of a ball is 4 m/s, v = 4 m/s (as it bounces)

Impulse provided by the wall is -3 N-m (impulse is provided in opposite direction)

We need to find the mass of the ball. Impulse provided to an object is given by the change in its momentum as :

J = m(v-u)

m is mass of the ball

$m=\dfrac{J}{(v-u)}\\\\m=\dfrac{-3}{(4-5)} \\\\m=3\ kg$

So, the mass of the ball is 3 kg.