# Thread: How do I do this formula for physics

1. ## How do I do this formula for physics

So the question is

1.)Using the average distance from the sun to the earth as 1 AU (astranomical units), determine the orbital period of a an asteroid which orbits the sun at a distance of 13 AU

I know I use kepler's 3 law (T2/t1)^2 = (r2/r1)^3

2. general form of kepler's third law
MP^2 = a^3

1)(1)(P^2)=13^3
2)P^2=2197
3)P=√2197=46.87 years ?

hope im right .

or could just P^2=a^3
still the same . i suck at physics

3. ## The Following User Says Thank You to Niku ・(￣∀￣)・ For This Useful Post:

Farting Scum (02-10-2015)

4. ## The Following User Says Thank You to Aborted For This Useful Post:

Farting Scum (02-10-2015)

6. kepler I hate this guy

7. Originally Posted by Niku ・(￣∀￣)・
general form of kepler's third law
MP^2 = a^3

1)(1)(P^2)=13^3
2)P^2=2197
3)P=√2197=46.87 years ?

hope im right .

or could just P^2=a^3
still the same . i suck at physics
You're correct.

I wouldn't have helped him though.

8. Originally Posted by arunforce

You're correct.

I wouldn't have helped him though.
Done and solved

Close @arunforce

9. Originally Posted by arunforce

You're correct.

I wouldn't have helped him though.
ah thanks arun ! :> .

10. Originally Posted by DarkLordXYZ
kepler I hate this guy
But what about Kepler-444, the planet ?