Question

A ball with a mass of `8 kg` moving at `8 m/s` hits a still ball with a mass of `9 kg`. If the first ball stops moving, how fast is the second ball moving?

Answer 1

The velocity is `=7.11ms^-1`

Explanation:

We have conservation of momentum

`m_1u_1+m_2u_2=m_1v_1+m_2v_2`

Therefore,

`(8xx8)+(9xx0)=(8xx0)+(9xxv_2)`

`9v_2=64`

`v_2=64/9=7.11ms^-1`