Question

What is the center of oscillation?

Answer 1

Center of percussion is defined as the point on an extended massive object attached to a pivot and a perpendicular impact will produce no reactive shock at the pivot translational and rotational motions cancel when an impulsive blow is struck at the center of percussion. The center of percussion is usually discussed in the context of a bat, racquet, door, sword or other extended object held at one end.

Complete answer:
Center of oscillation is called the center of oscillation for the object suspended from pivot as a pendulum, meaning that a simple pendulum with all its mass concentrated at that point will have the same period of oscillation as the compound pendulum.
Center of oscillation is defined as a point where the mass of the pendulum is concentrated and period is unchanged and when the pendulum is moved back and forth it creates an oscillating movement. More the frequency of the pendulum less will be the time period of oscillation.
Therefore frequency is inversely proportional to the time period.

Note: Center of percussion which can be applied to swords. Being flexible objects, the sweet spot for such cutting weapons not only depends on the center of percussion but also on the flexing and vibrational characteristics. The center of percussion of a bat is related to the “sweet spot “but the latter is also related to vibrational bending of the object.