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Energy question

  1. Oct 24, 2011 #1
    I've got an answer to a question but i'm not sure if it's correct as i dont have the answers.

    A roller coaster train is propelled at 57m/s and towards a vertical part of track which has a height of 139m, what is the velocity of the roller coaster train when it reaches the top of the tower?
    I got that:
    Ek=Ep so
    1/2mv^2=mgh so m's cancel so 1/2v^2=gh
    so in relation to the questiom
    1/2(57)^2=1/2v^2 + gh (because energy is conserved so potential energy must be added)
    Then
    1624.5=1/2v^2 + 1363.6
    290.9=1/2v^2
    etc, etc and ended up with 22.84 m/s but i've no idea if this is correct as i've never come across a question like this before. does this seem right? Thanks
     
  2. jcsd
  3. Oct 24, 2011 #2
    It is correct.
     
  4. Oct 24, 2011 #3
    I think it's right, I am getting the same answer. But, I did it using a different method:
    v2=u2+2as

    u=57 m/s
    a=-g
    s=139 m
    (we have to find v)
     
  5. Oct 24, 2011 #4
    I got the same answer as you.
     
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