You are turning 90 RPM, with a propeller...

Question 1 / 2707066636eea28f7522a1c51b702

Question 1 of 2707066636eea28f7522a1c51b702

You are turning 90 RPM, with a propeller pitch of 24 feet, and an estimated slip of -3%. What is the speed of advance?

Question 1 of 27070

You are turning 90 RPM, with a propeller pitch of 24 feet, and an estimated slip of -3%. What is the speed of advance?

🔍 Key Concepts

• Propeller pitch speed formula: how to convert RPM and pitch (in feet) to speed through the water • Meaning of negative slip and how it changes the theoretical pitch speed • Unit conversions between feet per minute and knots (nautical miles per hour)

💭 Think About

• First, ignore slip: what is the theoretical speed in feet per minute using RPM and pitch? • After finding feet per minute, how do you convert that to knots using nautical miles and minutes in an hour? • Once you have the theoretical speed in knots, how does a -3% slip change that number: do you increase or decrease the speed, and by what factor?

✅ Before You Answer

• Be sure to convert feet per minute to knots correctly using 1 nautical mile = 6076 feet (or 6076.1) and 60 minutes per hour • Apply the -3% slip to the theoretical speed, not to the RPM or pitch directly • Compare your final speed in knots with the answer choices and check which one is closest to your computed value

Question 1 of 27070

You are turning 90 RPM, with a propeller pitch of 24 feet, and an estimated slip of -3%. What is the speed of advance?

19.2 knots

18.8 knots

20.6 knots

21.9 knots