* Velocity is a measure of both speed and direction.

* Uniform velocity means the body is moving at a constant speed in a straight line. There's no change in either speed or direction.

* Acceleration is the rate of change of velocity. If velocity isn't changing, then there's no acceleration.

Think of it this way:

* Imagine a car traveling at a steady 60 miles per hour on a straight highway. The car's velocity is uniform.

* Since the car is not speeding up or slowing down, and it's not changing direction, its acceleration is zero.