---
# System prepended metadata

title: Midterm Problem 108-1
tags: [Science and Life, 通識, Introduction to Astronomy, NTNU]

---

# Midterm Problem 108-1

#### [Back to Introduction to Astronomy](https://hackmd.io/@sophie8909/Hkhh8G1vH)
###### tags: `NTNU` `通識` `Science and Life` `Introduction to Astronomy`

## Hint
- How long does it take to rotate around the sun if the planet is at 9AU?
    - a=9AU
    - P^2^ ~ 9x9x9
    - P ~ $\sqrt{729}$ ~ 27 yrs
    - $P^2=\dfrac{4\pi^2}{GM}a^3$
