the diameter of each wheel of a car is 32 inches. at how many RPMs should the spin balancer be set to balance the tires at a speed of 60 mph?

Question

the diameter of each wheel of a car is 32 inches. at how many RPMs should the spin balancer be set to balance the tires at a speed of 60 mph?

Answer 1

The circumference of the wheel is 32π.

The trick here is to make your units work correctly then do the arithmetic.

32π in/revolution * 1 ft/12 in * 1 mi/5280 ft = 32π/(12*5280) miles per revolution

miles/revolution * n revolution/min * 60 min/hr = miles/hr

so that 32πn * 60/(12*5289) = 60 mph

and 32πn/)12*5280) = 1 and n = 12*5280/32π...use π=3.1416 to get an answer you can round off.