1. The problem statement, all variables and given/known data Two identical steel balls,each of diameter 25.4mm and moving in opposite directions at 5m/s,run into each other head-on and bounce apart.Prior to the collision,one of the balls is squeezed in a vise while precise measurements are made of the resulting amount of compression.The results show that Hooke's law is a fair model of the ball's elastic behaviour.For one datum,a force of 16kN exerted by each jaw of the vise results in a 0.2mm reduction in the diameter.The diameter returns to its original value when the force is removed. Compute an estimate for the kinetic energy of each of the balls before they collide. 2. Relevant equations 3. The attempt at a solution The mass of the two balls are not mentioned in the question,so how to find the kinetic energy?