Date:17 Aug 97 01:57:23From:Wayne McCandless <SR-71@usa.net>References:1

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In article <airliners.1997.1727@ohare.Chicago.COM> Wally, gordow@cts.com writes: >At the expense of sounding stupid, could anyone explain the >mathematical relationship of thrust(rocket or jet) and horsepower. >More precisely, how does one convert from one to the other. I can't >begin to relate how long and often I've pondered this question. Any >help would be greatly appreciated. Not a stupid question at all. You might want to try a bit of dimensional analysis to help work through the confusion: 1 HP = 33,000 lb-ft/min = 550 lb-ft/sec; right? -- and -- Thrust is in units of lb-force. Therefore, An engine pushing a plane along at a (true) airspeed of 550 ft/sec is delivering one horsepower for each pound of thrust it produces. Left as an exercise for the student: B747 sits at end of runway all 4 engines at full howl, brakes locked. Each engine is providing about 44K pounds of push. Velocity of plane is zero. How many horsepower is being delivered? Where does the ³missing² power go, if anywhere?