eli5 how a complete rotation of wheel measures the length of circumstance with the same rotation the inner portion having less circumstance also covers the same distance.

Question

Sorry circumference.

In: 0

Answer 1

The outer part of the wheel goes as you expect. The inner part of the wheel, in addition to rotating, is also “sliding” as it moves. So the distance that the inner part of the wheel travels through the rotation is its circumference (from rotating) plus additional distance because it is essentially pushed (without rotating) at each moment in time.

In physics, we’d say the difference is that the outer circumference is rotating without slipping and the inner circumference is rotating with slipping. Searching these terms should give you a good visual.