Negative Acceleration and Motion Reversal

Acceleration describes a change in velocity. That change can be a change in speed, a change in direction, or both. The acceleration vector points in the direction of the velocity change, not always in the direction the object is moving.

When an object slows down, its acceleration points opposite ...

When an object moves at a constant speed in a straight-line path, it is not involved in an accelerated motion. Instead, it accelerates either by speeding up or by slowing down.

However, on a curved path, even at a constant speed, the object's motion is always accelerated as its direction of motion is changing continuously. Hence, accelera...