How do you calculate the mass of the sun, Msun, using Kepler's third law (T2=4π2r3GMsun)?

Assume the period of the Earth is T=3.156×107 seconds and the Earth's distance from the Sun is 1.496×1011 meters.

1 Answer
May 13, 2017

Plug the given values into the given equation. Answer: 1.98955×1030 kg

Explanation:

Since we are given the equation:
T2=4π2r3GMsun
where T=3.156×107 seconds, r=1.496×1011 meters, π3.14 is the mathematical constant, and G=6.67×1011 as the gravitational constant, we can first solve for Msun with variables then substitute the given values to find Msun:

First, we will use variables to solve for Msun to avoid the amount of numbers in the equation:
T2=4π2r3GMsun
T2(GMsun)=4π2r3
Msun=4π2r3T2G

Now, we can substitute our given values:
Msun=4π2(1.496×1011)3(3.156×107)2(6.67×1011)

1.98955×1030 kg rounded to 5 decimals