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Homework Help: Power of skier Question

  1. Feb 8, 2006 #1
    In 2.0 minutes, a ski lift raises four skiers at constant speed to a height of 140 m. The average mass of each skier is 65kg. What is the average power provided by the tension in the cable pulling the lift?

    t= 2.0min(60s/1min) = 120s
    m = 65kg x 4 = 260kg

    Wnc = △Ek + △Ep
    Wnc = Ekf - Eki + Epf - Epi
    Wnc = -mv^2 + mghf
    Wnc = -1/2(v)^2 + 356720J

    P = [-1/2(v)^2 + 356720J]/ 120s

    i do not know v so i don't know how to solve this. have i made any errors? thanks in advance
  2. jcsd
  3. Feb 9, 2006 #2
    From what I can see..the velocity 'v' is irrelevant as there is no change in mechanical energy (constant speed)...you have almost solved it :smile:
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