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Homework Help: Lab report: pulling cart up a ramp, find efficiencies

  1. Oct 29, 2005 #1
    I am doing a lab report and something is wrong. I dont know if it is my results, or if it is my calculation.

    What we did was pull a cart up a ramp upside down (wheels facing up) with different masses and different angles of the ramp. We pulled it up with a spring scale calibrated in Newtons. The newtons were recorded and the height, distance, and angle of the ramp were in this chart. The sigificant digits are off but that shouldnt affect the results I am getting. The efficiencies are way over 100% which is maximum.

    Formulas that I used are

    Total Energy Input = force x distance
    Useful Energy Output = mass x gravitational energy x height
    Efficency = Energy output/ energy input x 100%

    The chart is not complete yet though.

    Attached Files:

  2. jcsd
  3. Oct 29, 2005 #2

    Chi Meson

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    Science Advisor
    Homework Helper

    I have to fix your words here-- this should read:

    total work input = force x distance
    useful work output = mass x gravitational field strength x height

    I haven't seen the chart yet (approval is pending) but let me take a few stabs:
    did you include the mass of the cart itself? (you should have)
    did you multiply the weight of the cart (in newtons) times "g"? (you should NOT have)
    did you convert grams to kilograms correctly? (200 g = 0.200 kg)
  4. Oct 29, 2005 #3

    problem solved
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