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Homework Help: Work, Energy and Power Question

  1. Jul 19, 2009 #1
    1. A train of mass 2.4*10^6 kg enters a 5 km stretch of track with a vertical rise of 40 m at a speed of 1.0 m/s and leaves at 3.0 m/s. Assuming that frictional drag is negligible, find:

    A) Each term of the equation Win = Delta K + delta U + Wout

    B) Average Mechanical Power delivered by the engine for the climb if it is done at constant acceleration.

    2. A) Win = Delta K + delta U + Wout
    K= 1/2*mv^2

    3. A)I can't seem to get the picture of what is happening. I know that Wout is zero since there is no frictional drag, but I don't get the 40m rise and 5 km stretch part.
    B) average power = Win/delta t, how do you get delta t?

    Please help, I'm really confused. Thanks.

  2. jcsd
  3. Jul 19, 2009 #2


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    Gold Member

    I believe it means that the track length measured along the slope is 5000 m; and the track rises 40 m above it's start point in that stretch.
    You can use one of the kinematic equations.
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