As the wheel rotates one time, it moves a distance that is equal to the circumference of a circle.
d = π * 7
This is approximately 22 cm. To solve this problem, we need to convert the average speed from miles per second to cm/s.
v = 2.2 mi/s * 5280 ft/mi * 12 in/ft * 2.54 cm/in = 354,055.68 cm/s
The next step is use the following equation to determine the distance it moves in 20 seconds.
d = v * t = 354,055.68 * 20 = 7,081,113.6 cm
To determine the number of revolutions, divide the distance by the circumference of the wheel.
N = 7,081,113.6 ÷ π * 7
This is approximately 322,000 times. I hope this is helpful for you! Happy new year.