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# Why earth moves around sun,not moon?

Note by Mangesh Kumar
3 years, 10 months ago

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Obviously the sun has more mass than the moon (so much that despite the distance, the sun has a stronger gravitational pull), therefore the earth will revolve around the sun (as does the moon). · 3 years, 10 months ago

Ok let's assume the earth travels in a circular path. To calculate the net centripetal force on the earth assuming the earth is in between the sun and moon, we must use universal gravitation.

$$\Sigma F = \frac{Gm_{sun}m_{earth}}{r_1 {}^{2}} - \frac{Gm_{earth}m_{moon}}{r_2 { }{ }^{2}}$$

Even though the distance of the moon to the earth is much smaller, the mass of the sun is much greater, so the gravitational force the sun exerts is greater. Hence there is a net centripetal force acting on the earth in the direction of the sun · 3 years, 10 months ago