A water wheel has a radius of 15 ft. A river passing through the water wheel turns the wheel at 11 revolutions per minute(rpm). What is the speed of the river in miles per hour?

Answer 1

what's the circumference of the wheel? 30pi

So, 30pi ft flows by 11 times per minute

That makes a river speed of 30pi*11 ft/min

Now convert that to mi/hr