A ball with a mass of 6kg is rolling at 24ms and elastically collides with a resting ball with a mass of 3kg. What are the post-collision velocities of the balls?

1 Answer
Jul 7, 2017

v1=8ms and v2=32ms

Explanation:

Momentum is conserved in all collisions, but an elastic collision is one in which both momentum and mechanical energy are conserved. For elastic collisions, we use these equations to determine unknown values:

v1=(m1m2m1+m2)v1o+(2m2m1+m2)v2o

v2=(2m1m1+m2)v1o(m1m2m1+m2)v2o

We are given m1=6kg,v1o=24ms,m2=3kg, and v2o=0

We can use each equation to solve for v1 and v2.

v1=(6kg3kg6kg+3kg)(24ms)+0

=8ms

v2=(2(6kg)6kg+3kg)(24ms)0

=32ms

You can verify this answer using momentum and energy conservation.