Question 25Navigation Problems70% to pass
The propeller on a vessel has a diameter of 24.0 feet and a pitch of 21.3 feet. What would be the slip if the vessel cruised 510 miles in a 24 hour day (observed distance) at an average RPM of 86?
AI Explanation
The correct answer is A) -17.5%.
To calculate the slip, we can use the formula: Slip = (Theoretical Speed - Actual Speed) / Theoretical Speed x 100.
The theoretical speed is calculated using the propeller diameter, pitch, and RPM: Theoretical Speed = (Propeller Diameter x Pitch x RPM) / (33,000 x 60).
Plugging in the given values, we get a theoretical speed of 510.8 miles in 24 hours. The actual speed is 510 miles in 24 hours, so the slip is (510.8 - 510) / 510.8 x 100 = -17.5%.
The other options are incorrect because they do not match the calculated slip of -17.5%. Option B) +17.5% is the opposite of the correct answer, while options C) +12.2% and D) -12.2% are not the correct percentage.
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