Q:

The tires on your bicycle have a radius of 8 inches. How many rotations does each tire make when you travel 700 feet? Round your answer to the nearest whole number. Please help me

Accepted Solution

A:
"One rotation" would be the circumference of the wheel, which is

C = 2*pi*r, or  (here)  C = 2*pi*(8 inches) = 16*pi inches.

                                                                       1 ft
Convert this to feet:  16*pi inches  times  ---------------
                                                                   12 inches

Here "inches" cancels out and you are left with (4/3)pi ft.

So, one rotation of the wheel moves you and your bike forward (4/3)pi ft.

Divide this into 700 feet:

700 ft            2100 
------------- = --------- rotations = 525 rotations (answer)
(4/3) pi ft        4