Question

What is a good definition of acceleration?

Answer 1

It's a change in speed or velocity

Answer 2

Acceleration is the rate of change of velocity. When the magnitude or direction of the velocity changes, we says that the motion is accelerated. Acceleration is mathematically expressed as

`a=(dv)/(dt)`

The units of accelerations are m/s². Acceleration is a vector quantity and can be positive or negative as well. When the velocity of an object increases, we call that as positive acceleration and when the velocity of an object decreases , we call that as negative acceleration.