What does negative acceleration indicate?

Negative acceleration, also known as deceleration, indicates that an object's speed is decreasing over time. This can occur when the force applied to an object works in the opposite direction of its motion, resulting in a reduction of its velocity. For example, if a car is moving forward and the brakes are applied, the negative acceleration causes the car to slow down.

In contrast, positive acceleration would suggest that the object is speeding up, moving in the direction of the applied force. Maintaining a constant speed would indicate zero acceleration, regardless of its direction. Moving in reverse may also involve negative acceleration if the object is slowing down while moving backward, but negative acceleration alone does not imply direction; it strictly refers to a reduction in speed. Therefore, the most accurate interpretation of negative acceleration is that it signifies the object is slowing down.