00:01
In this problem, the diameter of the bicycle wheel is given as 28 inches.
00:05
And this implies the radius of the wheel is half the diameter, which is 14 inches.
00:11
And we are also given the rpm of the bicycle wheel, which is 180 revolutions per minute, which means the bicycle wheel makes 180 revolutions in one minute.
00:23
And we have to find the speed of the bicycle.
00:29
Let's see how to find this.
00:30
So we use the standard conversion 1 revolution is equal to 2 pi r.
00:39
So therefore for 180 revolutions, since the bicycle wheel makes 180 revolutions in one minute, we can say that we multiply the right hand side by 180, which will give us 180 times 2 pi r.
00:57
And since the radius is in inches, we mark this as inches.
01:01
So basically the bicycle wheel when it makes 180 revolutions in one minute, it's traveling a distance of 2xr times 180 inches...