Answer:
16.1 MPH
Step-by-step explanation:
If the wheels have a radius of 15 inches, then the circumference of a wheel is 2πr = 2 * π * 15 ≈ 94.248 inches.
If the wheels turn at 3 revolutions per second, that mean the car is travelling 94.248 * 3 ≈ 282.74 inches/second.
There are 12*5280 = 63360 inches in a mile and 60 * 60 = 3600 seconds in an hour. So to convert from inches/second to miles per hour, we need to divide the inches per second figure by (63360/3600), which is 17.6, to get miles per hour (MPH).
So in this case, 282.74/17.6 gives you approximately 16.1 MPH.
