Question

This is one of those special bounce collisions that is perfectly elastic. It is worth knowing that when identical masses collide in this way, they TRADE velocities. A billiard ball of mass 0.839 kg and speed 0.406 m/s makes a head-on elastic collision with an identical billiard ball at rest. What is the kinetic energy of the second ball after the collision?

Answer 1

Answer:

0.069 J

Explanation:

mass of first ball (M1) = 0.839 kg

mass of second ball (M2) = 0.839 kg

initial velocity of first ball (U1) = 0.406 m/s

initial velocity of second ball (U2) = 0 m/s

For head on elastic collisions of equal masses, the velocities of the masses always changes.and this has also been clearly stated in the question. Hence the velocity if mass A will interchange with that of mass B after collision.

therefore

final velocity of first ball (V1) = 0 m/s

final velocity of second ball (V2) = 0.406 m/s

kinetic energy of second ball after collision = 0.5m$v^{2}$

= 0.5 x 0.839 x 0.406 x 0.406 = 0.069 J