Question #983f9

1 Answer
Jan 21, 2018

Just that its velocity changes over time.


Because of the definition of velocity as a vector, this means that an object changing its speed (in a straight line) or its direction in space are both considered as accelerating.

A typical example would be a satellite in a circular orbit, its speed is constant (otherwise it would change altitude and approach towards or recede from the earth) but its direction is continually altering. As a result it is accelerating, so must be acted upon by a net force - gravity.

The same argument applies to spinning objects, the constituent parts must be subject to acceleration.