The time in years, T, for one complete orbit of a planet around a star can be calculated from the equation:
T = √Kr^3
The average radius, in kilometres, of the planet’s orbit is r, and K is a constant that changes depending on the mass of the star.
1)
Rearrange the equation to isolate K.
Then calculate for K for Earth’s solar system knowing that Earth takes one year to go around the sun and that the radius of Earth’s orbit is 1.49 x 10^8 km from the sun.
2)
Calculate how many Earth years it takes Neptune to complete an orbit. Neptune’s average orbital radius is 4.5 x 10^9 km.
