A cue ball of inertia m is given a speed v before it collides elastically with a full rack of 15 stationary balls in a game of pool. Each of the 16 balls has an inertia m. What is the average speed of each ball after they fly apart? Express your answer in terms of some or all of the variables m and v.

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?