Which is an example of the force of gravity of the earth

• GP Motion Force

Which one of the following is an example of the force of gravity of the earth acting on a vibrating pendulum bob?

1. Applied force
2. Frictional force
3. Restoring force
4. Virtual force

Answer

Every SHM (Simple Harmonic Motion) needs a restoring force. In case of pendulum restoring force is:

The correct option is C.