Question

A ball with a mass of `4 kg` moving at `6 m/s` hits a still ball with a mass of `10 kg`. If the first ball stops moving, how fast is the second ball moving? How much kinetic energy was lost as heat in the collision?

Answer 1

This is a conservation of momentum problem.
Calculate the system momentum before and after and solve for the speed of the second:

`m_1v_1 + m_2v_2 =m_1v_ 1^'+ + m_2v_2^' =`
Where `m_1=4kg; m_2=10kg; v_ 1=6m/s; v_2 =0`;

Substitute and solve... I will let you take it to the finish line...

for kinetic information find the energy before the collision:
`KE_i=1/2m_1v_1^2; KE_f=1/2m_2v_2^2;`
The difference:

`KE_i- KE_f`
`1/2m_1v_1^2 - 1/2m_2v_2^2;`

Is the energy loss

Good luck,
Yonas