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Homework Help: The relationship between Kinetic Energy and Position

  1. Nov 22, 2012 #1
    So Im writting a lab, and one of the testable questions required me to come up with a relationship between position and kinetic energy.

    In the lab a cart is released on a ramp and the end point of the cart is used as the reference point (h=0). We formed a position time graph and we are proving that energy is conserved (as long as gravity is the only force acting on the cart).

    I need to find the relationship between position of the cart on the ramp and the kinetic energy is possesses.

    I was thinking that it varies inversely, but I need to know why.
  2. jcsd
  3. Nov 22, 2012 #2


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    Can you please specify a little more clearly how you are defining "position of the cart"? Is it the vertical height of the cart, the distance along the ramp from the bottom of the ramp, the distance along the ramp from the release point, or something else?
  4. Nov 22, 2012 #3

    Simon Bridge

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    Taking h for height - from your observations, does the cart slow down or speed up as it loses height? How is kinetic energy related to speed? What about potential energy?
  5. Nov 22, 2012 #4
    Im refering to position as the distance it is from the final position (h=0 at final position).

    Here is my observation chart, maybe it can help.

    http://img841.imageshack.us/img841/4217/chart8c.png [Broken]
    Last edited by a moderator: May 6, 2017
  6. Nov 22, 2012 #5

    Simon Bridge

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    Can't make that image out - it is very small.
    Please read post #2 ... is the final position lower or higher than the initial position?
    Does your data show that the cart is gaining or losing kinetic energy as it approaches the final position?

    You have said what you measured h with respect to but not what h is a measure of ... there are lots of ways to measure the position of something. i.e. is it the horizontal distance to the cart? The vertical distance to the cart? The straight line distance to the cart? The distance along the track? Something else?

    However, you should be able to work out the answer you want by considering the comments above and in post #3. You could also plot a graph of kinetic energy vs distance from your data.
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