A billiard ball collides with a second identical ball in an elastic head-on collision. What is the kinetic energy of the system after the collision compared with the kinetic energy before the collision

Explanation:

From the question, we were made to understand that the collision between the two billiard balls was an elastic collision. Hence, an elastic collision is one in which the kinetic energy is conserved. Meaning the kinetic energy before the collision is still retained after the collision.

Kinetic energy before collision = kinetic energy after collision

1/2mv^2 = 1/2mv^2

There was no gain nor loss in energy

12000j is work done

measuring things 1 litre of water