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Homework Help: Potential vs. Kinetic Energy

  1. Sep 29, 2012 #1
    1. The problem statement, all variables and given/known data
    A San Francisco cable car loses its brakes and runs down a hill 30 m high. Assuming there is no friction, which of the following represents the energy changes that occurred?

    a. potential energy to kinetic energy
    b. kinetic energy to potential energy
    c. potential energy to heat energy to kinetic energy

    2. Relevant equations
    Potential Energy - The energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.
    Kinetic Energy - Energy that a body possesses by virtue of being in motion.

    3. The attempt at a solution
    a. potential energy to kinetic energy

    Is the correct answer a.?
  2. jcsd
  3. Sep 29, 2012 #2


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    Given the choices, why do you say 'a' is correct? Please explain.
  4. Sep 29, 2012 #3
    At the top of the hill, while the car is parked, it has potential energy. While the car is going down the hill it has kinetic energy because it is in motion. I don't think heat energy was produced because there was no friction. So that's why I picked a. :smile:
  5. Sep 30, 2012 #4
    That is right ! :)
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