## Circular Motion

A body is accelerating if the direction or the speed of the body is changing. A body moving in a circle can have a constant speed, but since the direction is contant changing, it is accelerating.

As with any body undergoing acceleration, a force is required. For a body of mass
$m$
with speed
$v$
$r$
$a=\frac{v^2}{r}$
$F=\frac{mv^2}{r}$
$F=ma$