Planet Average?

Question

If a planet has and average distance from the sun of 10 AU, what would its orbital period be?

Answer 1

i checked , it's right

Answer 2

Kepler's Third Law states:

"The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis (the "half-length" of the ellipse) of its orbit. This means not only that larger orbits have longer periods, but also that the speed of a planet in a larger orbit is lower than in a smaller orbit.

Without knowing how elliptical this planet's orbit is, we can only approximate.

If the average distance is 10 AU, lets take that as the semi-major axis.

Cube that gives us 1000.  The square root of that is 31.6.

So its orbital period is approximately 31.6 Earth years.

I think this is right, perhaps a math whiz can check this for us.