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Homework Help: Elevator going down; Main energy transformation?

  1. Apr 29, 2012 #1
    1. The problem statement, all variables and given/known data
    Hi! In the attachment :)

    3. The attempt at a solution
    Okay! By looking at the question I would've intuitively guessed that the answer would've been perhaps A. gravitational energy→kinetic energy! But then I thought of the P=F*v formula. If the elevator is going down at a constant speed, then it's not given a lot of KE (i would think!) . And since it's going downwards, It's also losing potential energy. What i'm confused about then is where the energy goes. Does the elevator engine need to provide any power in going down? I would've thought gravity would do the work! Could anybody give me any useful leads/tips? I've found that the answer is D but am still kind of at a loss with this one. Thankyou in advance!

    Attached Files:

  2. jcsd
  3. Apr 29, 2012 #2


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    What does kinetic energy depend on? By that I mean, what determines kinetic energy? Because if what determines it doesn't change, then it cannot change.
  4. Apr 29, 2012 #3
    Hmm. Velocity and mass. Which are cosntant...! So kinetic energy doesn't change to another form of energy, then?
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