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Homework Help: The Gravitational Force

  1. Oct 4, 2009 #1
    A planet has an euqatorial radius of 7.58 * 10^7 m and mass of 6.15 * 10^26 kg. Compute the acceleration of gravity at the equator of this planet.
    I used the formula f=G (m1*m2)/(r^2)

    i plugged it into the formula
    f= (6.674 *10^-11) (6.15 *10^26)/((7.58 * 10^7)^2)= 7.1437N

    accerleration= 7.1437/6.15 *10^26=1.1616 * 10^-26

    but the answer is wrong, what am i doing wrong??
  2. jcsd
  3. Oct 4, 2009 #2


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    Homework Helper

    What you did here was calculate GM/r2.

    Acceleration due to gravity is defined as F/m or simply GM/r2. So you found the acceleration due to gravity already, so your 7.1437N is really supposed to be 7.1437m/s2
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