Question

A To and Fro motion where the restoring force on the moving object is directly proportional to the object's displacement and acts towards the object's equilibrium position is known as ____________.
1. Periodic motion
2. Circular motion
3. Simple Harmonic Motion
4. Non Periodic Motion

Answer 1

Correct Answer - Option 3 : Simple Harmonic Motion

CONCEPT:

• Periodic motion: A motion that repeats itself after a period is called periodic motion.
  • Examples are the motion of the earth around the sun, the motion of a simple pendulum.
• Circular Motion: A motion in which a body moves in a circle is called circular motion.
• Simple Harmonic Motion: It is a special type of periodic motion in which there is a to and fro motion about a mean position and the restoring force is directly proportional to the object's displacement magnitude from the mean position and acts towards the object's mean position.
• Non-Periodic motion: A motion that does not repeat itself is called non-periodic motion.

EXPLANATION:

• Simple harmonic motion occurs when the restoring force is directly proportional to the displacement from equilibrium.

F α -x

Where F = force and x = the displacement from equilibrium.

• The negative sign tells that direction of force is opposite to displacement from the equilibrium position i.e. towards the equilibrium position.
• It is a to and fro motion about its equilibrium position.
• So the correct answer is option 3.