Question

A 0.35-kg tennis racquet moving to the right at 20 m/s hits a 0.06-kg tennis ball that is moving to the left at 30 m/s. After the collision, the racquet continues to the right, but at a reduced speed of 10 m/s. What is the ball's velocity after the collision?

Answer 1

From conservation of momentum we have that:

`0.35(20)-0.06(30)=0.35(10)+0.06v`

Solving for v we have that:

`\begin{gathered} 0.35(20)-0.06(30)=0.35(10)+0.06v \\ 7-1.8=3.5+0.06v \\ 0.06v=7-1.8-3.5 \\ 0.06v=1.7 \\ v=(1.7)/(0.06) \\ v=28.33 \end{gathered}`

Therefore the velocity of the ball after the collision is 28.33 m/s