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Homework Help: Final velocity problem involving a roller coaster changing height

  1. Jun 29, 2011 #1
    A roller coaster (475kg) passes point C with a velocity of 10.0 ms-1, calculate the velocity of the roller coaster at point A.

    mass = 475 kg
    velocity at C = 10 ms-1
    height at A = 30m
    height at B = 0m
    height at C = 25m
    height at D = 12m

    Ep = mgh
    Ek = 1/2mv^2

    The trolley is moving from Point C towards point A.

    *My method of finding out the answer was incorrect so you might want to ignore the following*

    I substituted the data given into Ep = mph (h at point A) and got Ep = 139,650J

    Then said Ep = Ek and subbed the data into Ek and got final velocity = 24.5 ms-1

  2. jcsd
  3. Jun 29, 2011 #2


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    Apply the conservation of mechanical energy. What does it say?

  4. Jun 29, 2011 #3
    I'm sorry but we have not come across mechanical energy yet and I am sure it was not used in working out the answer.
  5. Jun 29, 2011 #4


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    So what are Ep and Ek?

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