Inertia

An object that is stationary is an object that has zero velocity and zero acceleration. This is caused by a balanced force, which keeps the object stationary. There are only two forces acting being exerted on the object in this circumstance. The downward force of gravity cancels out with the upward force of the table. In our occurrence with the Ping-Pong balls the force of gravity has the same magnitude as the table, resulting in the Ping-Pong ball staying at rest.

 

V = 0

A = 0

ΣF = 0