Question

11. A bicycle traveled a distance of 100 meters. The diameter of the wheel of this bicycle is 40 cm. Find the number ofrotations of the wheel.

Answer 1

79.5 rotations

1) We can find the number of revolutions, so let's start out by finding the perimeter.

2) The perimeter of a circumference, and therefore the wheel is?

`P=2\pi r\Rightarrow P=2\pi(20)\Rightarrow P=40\pi\Rightarrow125.7cm`

Note that the radius is half the diameter so r = 20 and we rounded it off to the nearest tenth.

Now that we know the perimeter, let's divide the traveled distance by the perimeter, note that we need to convert the units:

`(100)/(40\pi*(1)/(100))=(100)/((40\pi)/(100))\approx79.577`

So the number of rotations is 79.5 rotations for 100 meters.