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Homework Help: Finding the mass of the sun

  1. Jan 28, 2010 #1
    Use your average value of G to estimate the mass of the Sun. Assume that the orbit of the Earth around the Sun is circular. The orbital radius of the Earth on its path around the Sun is R=1.5X10^11 m and the Earth needs 365.25 days for one full orbit. You need to provide detailed steps how you found the results and all equations used. (G=6.578X10^-11 N m^2/kg^2)

    Ok sooooo I tried the equation:

    so that became:
    Ms= 4(pi)^2 (1.5X10^11)^3/(6.578X10^-11)(31557600sec)
    Ms=(39.478 X (1.5X10^11)^3)/ (6.578X10^-11)(31557600sec)
    Ms=(39.478 X (3.375 X 10^33))/(6.578X10^-11)(31557600sec)

    Apparently that is wrong. I know that I did the correct steps. I guess somehow I went wrong in the exponents but I could have sworn that I did them correctly on the calculator. If anyone has any ideas how I messed up and could explain how the heck to fix this that would be amazing.
  2. jcsd
  3. Jan 28, 2010 #2


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    Homework Helper

    Don't forget that it's T2. You didn't do that in your calculation.
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