The example that is NOT an example of Simple Harmonic Motion is:
A ball rolling down a hill.
Simple Harmonic Motion is a type of periodic motion where the restoring force is proportional to the displacement from equilibrium and is directed towards the equilibrium point. The classic example of simple harmonic motion is the motion of a mass attached to a spring that is oscillating back and forth. Other examples of simple harmonic motion include a pendulum swinging back and forth and the vibration of a guitar string.
A ball rolling down a hill does not exhibit simple harmonic motion because it does not have a restoring force that is proportional to the displacement from equilibrium. The motion of the ball is affected by the force of gravity, which is not directed towards the equilibrium point, and the frictional force between the ball and the surface of the hill, which is not proportional to the displacement from equilibrium. Therefore, it is not an example of simple harmonic motion.