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Homework Help: Roller Coaster Problem Please Help

  1. Sep 11, 2012 #1
    1. The problem statement, all variables and given/known data

    http://img684.imageshack.us/img684/4316/capturerey.jpg [Broken]

    2. Relevant equations

    3. The attempt at a solution
    I am completely stuck on this. I thought I would use W=F=ma, but that wouldn't take the height into account. Any help would be greatly appreciated
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Sep 11, 2012 #2
    To find the velocity at the second peak, you can use conservation of energy:

    [itex]\displaystyle ΔU_g = mgΔh[/itex]
    Ug is potential gravitational energy

    [itex]\displaystyle K_E = -ΔU_g = \frac{1}{2} mv^2[/itex]

    And to find the apparent weight of the passenger, you can use the circular motion equation:

    [itex]\displaystyle F_{net} = \frac{mv^2}{r}[/itex]

    Hope that helps.
  4. Sep 11, 2012 #3


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    Yikes the heights are in meters but the weight is given in pounds. No wonder why they stopped teaching mixed units in the States. Watch your unit conversions, please.
  5. Sep 11, 2012 #4
    Thank you!
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