Here's why:

* Acceleration is a change in velocity.

* Velocity is speed *and* direction.

So, even if an object's speed is constant, but its direction is changing, it's still accelerating. For example, a car going around a curve at a constant speed is still accelerating because its direction is changing.

Here are some examples of objects accelerating:

* A car speeding up from a stop.

* A ball rolling down a hill.

* A rocket launching into space.

* A satellite orbiting Earth.

* A bicycle slowing down to a stop.

Important Note: Acceleration doesn't always mean an object is getting faster. It can also mean it's getting slower (decelerating) or changing direction.