A wooden block of mass M is resting on a horizontal surface. The coefficient of friction is f. One end of a spring with a spring constant k is attached to the block; the other end is attached to a solid wall. The spring is unstretched. A bullet of mass m hits the block and embeds in it. Find the velocity of the bullet before impact in terms of the maximum compression x of the spring and M, k, g, and f. 4.

A wooden block of mass M is resting on a horizontal surface. The coefficient of friction is f. One end of a spring with a spring constant k is attached to the block; the other end is attached to a solid wall. The spring is unstretched. A bullet of mass m hits the block and embeds in it. Find the velocity of the bullet before impact in terms of the maximum compression x of the spring and M, k, g, and f. 4.