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

Where the wheel contacts the ground, it isn’t actually moving unless the wheel slips. That is the only restriction a wheel has in how it moves relative to the ground, but it doesn’t continue up into the center of the wheel.

If we have a wheel and rotate it one rotation, it travels the circumference of the wheel. If we take the tire off of that wheel and rotate it once again, it has a smaller radius, and therefore a smaller circumference, and will go less far in that one rotation. This is because we change the point that has that restriction of needing to not move. The other points not having that restriction means that they can move relative to the ground, but there no slipping, since they aren’t touching the ground.