Question

One of the closest multiple-planet solar systems to our own is around the star Gliese 876, about 15 light-years away, and it contains four planets. One takes 63.8 Earth days to revolve, at a distance of 3.07 x 10^7 kilometers from Gliese 876. Another planet takes 130 Earth days to revolve. How far is this second planet from Gliese 876?

Answer 1

6.25 10^7 kilometers

Explanation:

We can calculate the distance of the second planet since it is proportional to the distance of the first planet, according to the days.

Therefore:

`\begin{gathered} (3.07\cdot 10^7)/(63.8)=(x)/(130) \\ \\ x=3.07\cdot10^7\cdot(130)/(63.8) \\ \\ x=6.25\cdot10^7\text{ km} \end{gathered}`

This means that the second planet is 6.25 10^7 kilometers from Gliese 876