Question

What does meant by "forth movement of a body" ?​

Answer 1

Explanation:

Vibration is a rapid back and forth movement of a body about a central position. Amplitude of an oscillation is the maximum displacement of the bob from its mean position during oscillation.

Answer 2

The back and forth movement of a body about a mean position referred to the movement in which the body travels backward and forward simultaneously about a mean position like a clock pendulum.