A negative acceleration tells you that the object's velocity is decreasing. Here's why:

* Acceleration is the rate of change of velocity.

* Positive acceleration means the velocity is increasing (the object is speeding up).

* Negative acceleration means the velocity is decreasing (the object is slowing down).

Important Note: Negative acceleration doesn't always mean the object is moving backwards. It simply means the object is slowing down in the direction it's currently moving.

Example:

Imagine a car traveling forward at 60 mph. If the driver applies the brakes, the car's velocity will decrease. This decrease in velocity is represented by negative acceleration.