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Average power output

  1. Nov 11, 2011 #1
    A man runs up 1576 steps in 9minutes 33sec. If the height gain of each step was 0.20m, and the mass of the runner was 70.0kgs, what was average power output during climb?
    I used P=W/T & W=FD
    W=70kg(1576)0.20=22,064J
    P= 22,064J/573s = 38.5 W
    answer given is380W
    What am I missing?
     
  2. jcsd
  3. Nov 11, 2011 #2

    SammyS

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    You used the man's mass. You should have used his weight.
     
  4. Nov 11, 2011 #3
    so W=70kg(9.81)(.2)(1576)=216447.84
    P=216447.84/573= 377.7W
    Close but not 380W
    Where is the discrepancy?
     
  5. Nov 11, 2011 #4

    SammyS

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    Significant digits?
     
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