If the speed necessary for reaching port at...

Question 1 of 2707066636eea28f7522a1c51b5be

If the speed necessary for reaching port at a designated time is 21.6 knots and the pitch of the propeller is 22.5 feet, how many revolutions per minute will the shaft have to turn, assuming a 2% positive slip?

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Question 1 of 27070

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🔍 Key Concepts

• Relation between ship’s speed in knots, propeller pitch in feet, and shaft RPM • Definition of positive slip and how it changes effective advance per revolution • Unit conversions between knots, nautical miles per hour, and feet per minute

💭 Think About

• First, convert the given speed in knots into feet per minute so it can be compared with pitch in feet per revolution • Write the ideal (no-slip) relation between advance speed, pitch, and RPM, then adjust it for a 2% positive slip • After computing the theoretical RPM, compare the result with the multiple-choice options and see which is closest

✅ Before You Answer

• Be sure you convert knots to feet per minute correctly before using the pitch value • Remember that positive slip means the vessel advances less than the theoretical pitch per revolution • Check your final RPM against each option and confirm that the units are revolutions per minute, not per hour