Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook