Question

two cars collide head on. Car A has a mass of 1000 kg car B has a mass of 2000 kg. What is the speed of car B after the collision?

Answer 1

Explanation :

It is given that :

Mass of car A,
`m_A=1000\ Kg`

Mass of car B,
`m_B=2000\ Kg`

Let, the speed of car A and B after collision are
`v_A` and
`v_B` respectively and
`u_A` and
`u_B` be their initial velocities.

We know that in head on collision, momentum remains conserved.

so,
`m_Au_A+m_Bu_B=m_Av_A+m_Bv_B`

so,
`v_B=(m_Au_A+m_Bu_B-m_Av_A)/(m_B)`
`v_B=(1000u_A+2000u_B-1000v_A)/(2000)`

so,
`v_B=u_A+2u_B-v_A`

Hence, the speed of car B is
`v_B=u_A+2u_B-v_A`