Gravity on mass on earth's surface vs sun-earth gravity

  1. Q:
    A mass of 5.000 kg is sitting on the Earth's surface directly under the sun during a solar eclipse. The sun exerts a gravitational force with magnitude Fs on the mass. The moon's gravitational force on the mass has magnitude Fm. Calculate the ratio Fs / Fm.

    This problem is really frustrating me. For the object, wouldnt Fm be mg = 5*9.8?

    Then wouldnt the Fs be (mass of the sun)(mass of earth)/R^2 ?

    So wouldnt it be the Fs divided by Fm? Please help!?!?!
  2. jcsd
  3. OlderDan

    OlderDan 3,029
    Science Advisor
    Homework Helper

    You are being asked to calculate the ratio of the forces of attraction to the sun and to the moon for a mass that is at the surface of the earth. You are not asked for the force of attraction to the earth.
  4. HAH wow i'm embarassed... thanks :blushing:
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