Question

A rocking chair is an example of

• A. Periodic motion
• B. Translatory motion
• C. Rotatory motion
• D. None of the above

Answer 1

The correct option is A Periodic motion

Periodic motion is any motion that recurs in identical forms at equal intervals of time.
A motion that is regular and repeating is referred to as a periodic motion. Most objects that vibrate do so in a regular and repeated fashion; their vibrations are periodic.
Examples of periodic motion:
Periodic motion is performed by a rocking chair, a bouncing ball, a vibrating tuning fork, a swing in motion, the Earth in its orbit around the Sun, and a water wave. In each case the interval of time for a repetition, or cycle, of the motion is called a period, while the number of periods per unit time is called the frequency. Thus, the period of the Earth's orbit is one year, and its frequency is one orbit per year. A tuning fork might have a frequency of 1,000 cycles per second and a period of 1 millisecond (1 thousandth of a second).
Simple harmonic motion is a special case of periodic motion. In the examples given above, the rocking chair, the tuning fork, the swing, and the water wave execute simple harmonic motion, but the bouncing ball and the Earth in its orbit do not.