If a body is moving with constant velocity, its acceleration is zero.

Here's why:

* Acceleration is the rate of change of velocity.

* If velocity is constant, it means there is no change in velocity over time.

* Since there is no change in velocity, the acceleration is zero.

Example:

Imagine a car driving down a straight road at a steady 60 miles per hour. The car's velocity is constant. Since the velocity isn't changing, the car is not accelerating.