The speed of advance necessary to arrive in...

Question 1 of 2707066636eea28f7522a1c51b59b

The speed of advance necessary to arrive in port at a designated time is 15.8 knots. The pitch of the propeller is 20.75 feet. You estimate 5% positive slip. How many revolutions per minute must you turn to make the necessary speed?

Back

Question 1 of 27070

🔍 Key Concepts

• Relationship between speed, distance, and time in knots and nautical miles • How propeller pitch, slip, and revolutions per minute (RPM)** are related • Converting between knots, nautical miles per hour, feet per minute, and revolutions per minute

💭 Think About

• First, convert the ship’s speed in knots into feet per minute so it matches the pitch units in feet • Figure out the effective distance advanced per revolution when there is 5% positive slip (compare ideal pitch vs. actual advance) • Use the relationship: speed (ft/min) = advance per rev (ft/rev) × RPM, then solve for RPM and compare to the choices

✅ Before You Answer

• Be sure you apply the 5% positive slip to reduce the effective advance per revolution, not increase it • Check all your unit conversions: knots → nautical miles per hour → feet per hour → feet per minute • After calculating RPM, see which multiple-choice option is numerically closest to your computed value, watching for rounding differences