PhysicsLAB: 2002 B2

A 3.0 kg object subject to a restoring force F is undergoing simple harmonic motion with a small amplitude. The potential energy U of the object as a function of distance x from its equilibrium position is shown above. This particular object has a total energy E of 0.4 J.

	(a) What is the object’s potential energy when its displacement is +4 cm from its equilibrium position?

	(b) What is the farthest the object moves along the x-axis in the positive direction? Explain your reasoning.

	(c) Determine the object’ s kinetic energy when its displacement is —7 cm.

	(d) What is the object’ s speed at x = 0?

Suppose the object undergoes this motion because it is the bob of a simple pendulum as shown below.

	(e) If the object breaks loose from the string at the instant the pendulum reaches its lowest point and hits the ground at point P shown, what is the horizontal distance d that it travels?