Circular motion is motion around a circular path. It may have a
constant speed, or it may speed up, slow down, stop for a while,
then start up suddenly, proceed in jumps, then slowly peter out
again until it's barely crawling, then accelerate to such a high speed
that the track starts smoking.
If the circular motion is at a constant speed and doesn't speed up
or slow down, then it's called 'uniform' circular motion.
