What is an essential characteristic of an object in equilibrium?

zero velocity
zero acceleration
zero momentum
zero energy

Zero Acceleration.

Explanation:

If an object is at equilibrium, then the forces are balanced. Balanced is the key word that is used to describe equilibrium situations. Thus, the net force is zero and the acceleration is 0 m/s/s. Objects at equilibrium must have an acceleration of 0 m/s/s.

b.

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