Question

A ball with a mass of `12 kg` moving at `7 m/s` hits a still ball with a mass of `17 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

The answer is `V_2 =4.94 ~5`
And loss in KE = 87.89 joule or 88 joules approx

Explanation:

According to the conservation of momentum
`m_1v_1+m_2v_2= m_1V_1+m_2V_2`

`12** 7 = 17** V_2`
`V_2=4.94m//s`

Now `Delta KE=1//2(m_1m_2//m_1+m_2)(1-e^2)(v_1-v_2)^2`

And e= relative velocity of separation`//`relative velocity of approach.

Solving it we get the value of loss in KE :)