Sometimes, file center of oscillation is termed as center of percussion. It is defined as that point at which a blow may be struck on a suspended body so that the reaction at the support is zero. It may be noted that

1. The center of percussion (C) is below the center of gravity (G), as shown in Fig. 1.36, and at a distance of

2. The distance between the center of suspension (O) and the center of percussion (C) is

equal to the equivalent length of simple pendulum, i.e.

L = l + h

3. The center of suspension (O) and the center of percussion (C) are inter-changeable.