That means that when an object slows down, it has a negative acceleration. (Note: This assumes motion in one dimension.) Here’s an example: Suppose two people are each standing on a skateboard.

Revise how acceleration relates to speed or velocity and distance and how to carry out calculations as part of BBC Bitesize Scotland National 5 Physics.

Learn the uses of equations and graphs of motion and how to determine other aspects of the motion of objects. BBC Bitesize Scotland Higher Physics revision.