Periodic Motion: Oscillation of a Pendulum

Introduction:
Periodic motion refers to the motion of an object that repeats itself after a regular interval of time. It is characterized by the repeated back-and-forth movement or oscillation of an object around a fixed point or equilibrium position. One example of periodic motion is the oscillation of a pendulum.

Oscillation of a Pendulum:
The oscillation of a pendulum is a classic example of periodic motion. A pendulum consists of a weight (also called a bob) suspended from a fixed point by a string or rod. When the pendulum is displaced from its equilibrium position and released, it swings back and forth in a regular pattern.

Key Points:
- The pendulum moves to one side, reaches its maximum displacement, and then starts moving back towards the other side.
- As it swings, the pendulum goes through a cycle of motion that is repeated over time.
- The time taken by the pendulum to complete one full cycle (from one extreme to the other and back) is called its period.
- The period of a pendulum depends on its length and the acceleration due to gravity.
- The period of a pendulum remains constant as long as the length and acceleration due to gravity remain unchanged.

Characteristics of Periodic Motion:
Periodic motion, such as the oscillation of a pendulum, exhibits the following characteristics:
1. Regular Repetition: The motion repeats itself in a regular pattern, with each cycle being identical to the previous ones.
2. Fixed Time Interval: The time taken for one complete cycle remains constant.
3. Restoring Force: There is a force acting on the object that drives it back towards the equilibrium position, restoring its original state.
4. Equilibrium Position: The object has an equilibrium position, where the restoring force is zero, and it experiences maximum potential energy.

Conclusion:
The oscillation of a pendulum is a clear example of periodic motion. It demonstrates the regular back-and-forth movement of an object around a fixed point. The motion repeats itself in a fixed time interval, and the pendulum swings back and forth due to the restoring force acting on it. Thus, option A - oscillation of a pendulum - is the correct example of periodic motion among the given options.