Here's why:
* Acceleration is a vector quantity: This means it has both magnitude (how much) and direction.
* Change in velocity: Acceleration is defined as the rate of change of velocity. Velocity, like acceleration, is also a vector quantity.
* Changing direction changes velocity: Even if the speed (magnitude of velocity) stays the same, changing direction means the velocity vector is changing.
* Changing velocity means acceleration: Since acceleration is the change in velocity, a change in direction results in acceleration.
Example:
Imagine a car driving at a constant speed around a circular track. Even though the car's speed is constant, it is constantly changing direction, which means its velocity is changing. This change in velocity means the car is accelerating.
Key Point: Acceleration doesn't always mean speeding up. It can also mean slowing down (deceleration) or changing direction.
