Question

a 30 kg mass moving at 18 m/s collides with a 90 kg mass moving at 14.4 m/s in the opposite direction.the collision is elastic and head on.find the velocity of each mass after the collision.​

Answer 1

Answer:

6.3 m/s.

Explanation:

Since, both of the bodies approaching each other in opposite direction after colliding with each other will be having same initial momentum and final momentum.

So, the initial momentum of the 30 kg mass will be 30*-8 which is -540 kg m/s. The initial momentum of the 90 kg mass with velocity in opposite direction will be 90*-14.4 = 1296 kg m/s. So, the initial momentum will be 1296-540 which on solving we will get 756 kg m/s. While the final momentum with velocity vf will be 90+30=120*vf. So, 120vf=756 which on solving we will get the velocity as 6.3 m/s.

Answer 2

Answer:

Answer is -30.6m/s, 1.8 m/s.

I hope it helps you