Properller Size An ideal diameter d, in feet, of a ship’s propeller is given by the formula
Here h is the horsepower of the engine driving the properller, and r is the (maximum) revolutions per minute of the properller.
a. The Victory Ships produced in Wolrd War II had and engine that produced 6000 horespower and rotated the prepeller at 100 revolutions per minute. According to the formula, what should have been the diameter of their properllers? (The actual diameter was 18.2 feet.)
b. If a ship’s engine has a horsepower of 8500 turning a propeller with a diameter of 20 feet, what should be the (maximum) revolutions per minute of the propeller?
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