What is the efficiency of the aircraft engines in this scenario?

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The discussion centers on calculating the efficiency of aircraft engines based on power output and energy requirements during ascent. The aircraft weighs 3.25 * 10^3 kg, reaches a cruising altitude of 10 km in 12.5 minutes, and maintains a speed of 850 km/h with engines providing an average of 1500 hp. Initial calculations yielded an efficiency of 14.6%, while the correct efficiency should be around 48.7%. Participants emphasize the importance of unit conversions, including changing minutes to seconds, kilometers to meters, and horsepower to watts. Ultimately, the correct efficiency calculation hinges on accurate unit conversions and proper energy calculations.
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A 3.25 * 103-kg aircraft takes 12.5 min to achieve its cruising altitude of 10.0 km and cruising speed of 850 km/h. If the plane's engines deliver, on the average, 1500 hp of power during this time, what is the efficiency of the aircraft engines?

I initially believed the power out would be: (Kinetic energy + Potential energy)/Time

And efficiency would be 1500hp/power out. But after my calculations, I got 14.6% efficiency, when it should be 48.7% efficiency.

What did I do wrong?
 
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I calculated 48.8% efficiency.

Did you...

1) Change minutes to seconds?
2) Change km to m?
3) Change km/h to m/s?
4) Convert J to hp? ( 735.498 75 watt = 1hp/s)

You have to do each of those in this problem.
 
Check your units. Did you convert the power in hp to watts?

1 hp = 746 watts.
 
Looks like we typed at the same time.
 
I don't know what I did wrong.
I'm pretty sure I converted everything.
It must have been a calculation error, because I just got the right answer.
 

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