# Relationship between circular motion and sinusoidal oscillation

If you look at a uniform circular motion from the side, i.e. project it onto a straight line, you get a harmonic oscillation. One observes the change over time and the uniform circular motion becomes with the path speed $υ0$ described.

The radius $r$ means the maximum deflection, i.e. characterizes the amplitude of the oscillation.

The amount of speed $υ$ changes over time because a different proportion of the web speed at any given time $υ0$ when the circle falls in the projection direction. When the middle position is passed, the speed is with $υ=υ0$ is maximum and at maximum deflection $υ=0$.