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=\dfrac{m_Au_A+m_Bu_B-m_Av_A}{m_B}$$v_B=\dfrac{1000u_A+2000u_B-1000v_A}{2000}$

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

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