# Astronomy

posted by .

Suppose the Sun were twice as massive as it actually is. What would be the orbital period of a planet at a distance of 10AU from the Sun?

• Astronomy -

For the actual sun's mass, according to Kepler's third law,
P^2/a^3 = 1 = P^2/1000
P = 31.6 years

For a sun that is twice as massive, the centripetal gravity force is twice as large, so V must increase by a factor of sqrt2 to balance it.

The period will be lower by a factor 1/sqrt2 due to the higher speed

Period = 31.6/1.414 = 22.4 years

## Similar Questions

1. ### Math

The period of revolution of a planet around the sun is the time it takes for the planet to complete one orbit of the sun. The period, P years, is give by Kepler's third law P^2=D^3, where D is the average distance from the sun in astronomical …
2. ### physics

The mean distance of the planet Neptune from the Sun is 30.05 times the mean distance of Earth from the Sun. a.) Determine how many Earth-years it takes Neptune to orbit the Sun. b.) The mass of the Sun is 1.99 x 10^30 kg, and the …
3. ### Astronomy

Orbital speed is the speed with which a planet moves around the sun. The speed is determined by: a)the mass of the planet only b) the mass of the sun only c)both the mass of the planet and the mass of the sun d)the mass of the planet …
4. ### physics

The physics of orbital radius and orbital period of a planet. If a small planet were discovered whose orbital period was twice that of Earth, how many times farther from the sun would this planet be?
5. ### astronomy

suppose the sun were twice as massive a it actually is. What would be the orbital period of a planet at a distance of 10 AU from the sun?
6. ### Physics

A certain planet is located 3.54 x 10^11 m from its sun. If its orbital period is 4.9 x 10^7 s, find the mass of its sun.
7. ### Physics

A certain planet is located 3.54 x 10^11 m from its sun. If its orbital period is 4.9 x 10^7 s, find the mass of its sun.
8. ### Astro

A newly discovered planet orbits a distant star with the same mass as the Sun at an average distance of 118 million kilometers. Its orbital eccentricity is 0.5. A.Find the planet's orbital period. B.Find the planet's nearest orbital …
9. ### physics

If a small planet were discovered whose orbital period was twice that of Earth, how many times farther from the Sun would this planet be?
10. ### Science

What distance was used to define the astronomical unit (AU) A. the average distance across the sun, its diameter B. the average distance from the sun to mercury, the closest planet C. the average distance from the sun to earth, our …

More Similar Questions