# Question #c9b31

$F = m {v}^{2} / r$
For a particle moving at constant speed in a circle, the magnitude of its inward radial acceleration is $a = {v}^{2} / r$, which is clearly a constant value. Bt Newton's Second Law, the magnitude of the accelerating force (also inward radial) is therefor $F = m {v}^{2} / r$, again a constant value.