Which of the following examples represent simple harmonic motion and which represent periodic but not simple harmonic motion?

Options

A. The rotation of earth about its axis.
B. Motion of an oscillating mercury column in a U tube:
C. Motion of a ball bearing inside a smooth curved bowl, when released from a point slightly above the lower most position.
D. General vibration of a polyatomic molecule about its equilibrium position.

Explanation

a. It is periodic but not SHM because it isnot to and for morion about a fixed point.
b. It is SHM c. It is SHM
d. It is a periodic but not SHM A polyatmic gas molecule has a numbr of natural frequencies and its general motion is the resultant of SHMs of a number of different frequencies. The resultant motion is periodic but not SHM.