Question

A ball with a mass of 4 kg is moving with a velocity of 14.8 m/s. It hits a bat and rebounds with a new velocity of 5.3 m/s. What is the change in momentum of the ball?

Answer 1

Given:

mass of the ball is

`m=4\text{ kg}`

The velocity of the ball is

`v_1=14.8\text{ m/s}`

The velocity of the ball after rebounds is

`v_2=5.3\text{ m/s}`

Required:

we have to calculate the change in momentum of the ball.

Step-by-step explanation:

a ball moving with a certain velocity has a momentum P1 and after being hit by the bat, it has another momentum P2.

So , To calculate the change in momentum we will use formula

`\Delta P=P_2-P_1.....(1)`

we know the momentum is given as

`P=mv`

now equation (1) can be written as

`\Delta P=mv_2-mv_1`

plugging all the values in the above relation.we get

`\begin{gathered} \Delta P=4\text{ kg}*5.3\text{ m/s-4 kg}*14.8\text{ m/s} \\ \Delta P=21.2-59.2\text{ kg m/s} \\ \Delta P=-38\text{ kg m/s} \end{gathered}`

The negative sign shows that momentum has decreased.

Thus, the change in momentum of the ball is

`\Delta P=38\text{ kg m/s}`