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I need data from the Cavendish Experiment

  1. May 23, 2012 #1
    Hi guys

    I am doing a presentation on the cavendish experiment. But to show how it is done, I not only need to conceptually explain how it was done I need numbers so I can run it through equations so I can show the end result.

    I have scoured the internet for data table without any success. Is there anywhere where I can find some data for Cavendish's experiment?

    Also, in Cavendish's experiment, is it correct in deriving the equation for G by saying:

    Torque = Torsion constant x Theta
    Torque = Force x Radius

    Therefore, torsion constant x theta = force x radius.

    Then, force = (torsion constant x theta) / radius

    Then, force = Newton's Law of Gravitation

    Therefore, (torsion constant x theta) / radius = Newton's Law of Gravitation

    Then, torsion constant = (Newton's Law of Gravitation x radius) / (distance between two objects ^2) x Theta

    The next big chunk is

    Period = (2 x pi) x (( Moment of Intertia / Torsion Constant) ^-1)

    And moment of inertia is 2m(L/2)^2

    So Period = (2 x pi) x (( 2m(L/2)^2 / (Newton's Law of Gravitation x radius) / (distance between two objects ^2) x Theta

    If you're still reading, and I haven't lost you I got

    Gravitational Constant = ((4 x pi^2) x 2m(l/2)^2) / ((Period ^2) x radius (M x m / distance between two objects^2) x theta)

    For F*ck's sake, my goodness

    Well please help me out. I will be eternly grateful
  2. jcsd
  3. May 27, 2012 #2

    Simon Bridge

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    Since it is only a presentation you can run the whole thing backwards (work out what the data would look like knowing G and how it's done - randomize it slightly to simulate measurement uncertainties.)

    The physics is basically for a damped mass on a spring.
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