00:01
A reminder that in circular motion, tangential motions are related to angular ones through the radius.
00:11
So, for example, if something moves through an angle of delta theta, the linear motion it travels through is an arc length in meters, which is equivalent to the radius of the circle times the change in angle.
00:31
So that is how linear quantities are related to angular, as long as we are talking about tangent to the circle.
00:48
And where this comes into play is a lot of problems involving gears that are linked together, which can get quite complicated.
00:58
But here's a simple example of a bicycle wheel.
01:03
Now, there are two wheels on every bicycle, but they basically roll out the same linear distance as the bicycle moves.
01:15
So the linear distance the bicycle rolls out is equal to the radius of the bicycle wheel, which we show here as 0 .4 meters, times the angle through which the bicycle rolls.
01:31
We'll call that delta phi...