# Gravitational Accelaration

1. Mar 2, 2006

### avb203796

If an object were discovered oriting at a radius of 3*10^6 m, what would be the time that it would take to complete one orbit around the sun?
So I know I need to use the following equation:

T^2/R^3 = 4pie^2/GM

but do I use the radius they gave me or do I have to add that radius to the the radius of the sun to get R?

2. Mar 2, 2006

3. Mar 2, 2006

### Chi Meson

The radius in the formula is the radius of the circle of the orbit. However, the Sun's radius is quite a bit more than 3 million meters (The Earth's radius is 6 million meters)!

If this is exactly how the question is stated, the the question is flawed. Perhaps the problem was intended to be 3 million meters above the surface of the sun. In that case you would add 3*10^6 to the Sun's radius of 6.96*10^8 meters, which would be 6.99*10^8 meters. This is almost insignificant, but it would be my assumption as to what the intent of the question was.

Last edited: Mar 2, 2006