If the main propulsion turbine speed...

Question 1 of 270705eccefa1bacbc34ba4d472cf

If the main propulsion turbine speed percentage is increase from 30% to 60%, what percentage of horsepower is required when the new speed is attained as shown in the illustrated graph? See illustration SE-0018.

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Question 1 of 27070

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🔍 Key Concepts

• Read percentage horsepower from the vertical axis at a given percentage speed (RPM) on the horizontal axis • For propellers/turbines on a constant-pitch propeller curve, required horsepower changes roughly with the cube of the speed • Convert a percent value into a decimal fraction (e.g., 20% = 0.2) to match the answer choices

💭 Think About

• On the graph, what % horsepower does the curve show at 60% speed? Trace straight up from 60 on the bottom axis until you hit the curve, then across to the left axis. • Does the horsepower at 60% speed look closer to 10%, 20%, 30%, or 40%? Compare the curve’s position between the horizontal grid lines. • How does the idea that power is roughly proportional to the cube of speed help you estimate the horsepower needed at 60% of full speed?

✅ Before You Answer

• Be sure you are reading 60% speed, not 30% or 50%, on the bottom (horizontal) axis. • Double‑check the left (vertical) axis labels so you read the horsepower percentage correctly at that speed. • Before choosing, convert the graph’s horsepower percent to a decimal (e.g., 20% → 0.2) so it matches the style of the answer choices.