Two identical steel balls, each of diameter 24.8 mm and moving in opposite directions at 4 m/s, run into each other head-on and bounce apart. prior to the collision, one of the balls is squeezed in a vise precise measurements are made of the resulting amount of compression. the results show that hooke's law is a fair model for the ball's elastic behavior. for one datum, a force of 25 kn exerted by each jaw of the vise results in a 0.5-mm reduction in the ball's diameter. the diameter returns to its original value when the force is removed. modeling the ball as a spring, find its spring constant.