You are turning 105 RPM, with a propeller...

Question 1 of 2707066636eea28f7522a1c51b6f0

You are turning 105 RPM, with a propeller pitch of 17 feet, and an estimated slip of -1%. What is the speed of advance?

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Question 1 of 27070

Q

You are turning 105 RPM, with a propeller pitch of 17 feet, and an estimated slip of -1%. What is the speed of advance?

🔍 Key Concepts

• speed of advance (SoA) vs. speed through the water • relationship between RPM, propeller pitch, and theoretical speed • how slip percentage (including negative slip) changes the theoretical speed

💭 Think About

• First, calculate the theoretical speed in feet per minute using only RPM and pitch. What formula relates those three? • Then, apply the slip correction. With -1% slip, do you make the vessel faster or slower than the theoretical speed? How do you adjust the value? • Finally, convert your corrected speed from feet per minute to knots. What is the conversion factor between feet per second, nautical miles, and knots?

✅ Before You Answer

• Be sure you apply slip in the correct direction (negative slip increases speed slightly). • Confirm you are using nautical miles (6076 ft), not statute miles, for the final conversion to knots. • Double-check that your intermediate units go in order: RPM → ft/min → ft/sec → knots (or an equivalent clear path).