Which of the motions below is simple harmonic?

I. The motion of the tyres of a moving car.
II. The motion of a loaded test tube oscillated vertically.
III. The beating of the heart.
IV. A stone tied to a string and whirled round.
V. The motion of the pistons in a gasoline engine.

A. III, IV and V only
B. II, III and V only
C. II, III and IV only
D. I, II and III only

Correct Answer:

Option B – II, III and V only

Explanation

Simple harmonic motion is the motion of a body whose acceleration is directed towards a fixed point and is directly proportional to its displacement from point.