Question

A ball with a mass of `12 kg` moving at `1 m/s` hits a still ball with a mass of `8 kg`. If the first ball stops moving, how fast is the second ball moving?

Answer 1

`v_2'=1,5 m/s`

Explanation:

`P_1:" momentum of object with a mass of 12 kg before event"`
`P_1^':" momentum of object with a mass of 12 kg after event"`
`P_2:" momentum of object with a mass of 8 kg before event"`
`P_2^':" momentum of object with a mass of 8 kg after event"`
`P_1+P_2=P_1'+P_2'`
`"the momentum of an object equal zero if it has a velocity of 0"`
`m_1*v_1+0=0+m_2*v_2'`
`12*1=8*v_2'`
`v_2'=12/8`
`v_2'=1,5 m/s`