Chapter 5.2, Problem 12E

Reminder Round all answers to two decimal places unless otherwise indicated.

Ship Propellers An ideal diameter d, in feet, of a ship's propeller is given by the formula

$d=c{h}^{1/5}{r}^{-3/5}$.

Here $h$ is the horsepower of the engine driving the propeller. $r$ is the (maximum) number of revolutions per minute of the propeller, and $c$ is a constant. In both parts, give your answer in terms of a percentage.

a. If the horsepower is increased by $20\%$ while the number of revolutions per minute remains the same, how is the propeller diameter affected?

b. If the horsepower remains the same while the number of revolutions per minute is increased by $20\%$, how is the propeller diameter affected?