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

Homework Help: Time it takes to lift boxes when man has an average useful power output of 41.4 W

  1. Mar 20, 2010 #1
    1. The problem statement, all variables and given/known data
    If a man has an average useful power output of 41.4 W, what minimum time would it take him to lift fifty 15.0-kg boxes to a height of 1.88 m?


    2. Relevant equations
    1/2mv(final)^2 mgy(final) = 1/2mv(initial)^2 mgy(initial)

    P=W/Δt

    P=Fv

    3. The attempt at a solution

    Dont even know where to start
     
  2. jcsd
  3. Mar 20, 2010 #2

    ideasrule

    User Avatar
    Homework Helper

    How much energy is needed to lift those boxes?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook