1. Sep 3, 2008

Darkhrse99

I need to convert the earth's radius of 6.37 x 10^6 in to the km, But I need it to be the circumference in km.

I started out with 6.37x 10^6 times (1km/1000m) which gives me 6.37x 10^3. Now I need to convert to the circumference, but not sure how. The answer is 4.00x10^4. I don't see how 6.37x10^3 is going to come close to the answer. Where do I go from here?

Thanks
Jason

Last edited: Sep 3, 2008
2. Sep 3, 2008

Staff: Mentor

What is the formula for a circumference?

Last edited: Sep 3, 2008
3. Sep 3, 2008

Darkhrse99

I don't know?

4. Sep 3, 2008

Staff: Mentor

I find it hard to believe that you were not taught it earlier. But if not - check in your textbook, handbook or in wikipedia, or just google it.

5. Sep 3, 2008

Darkhrse99

Sorry about that. I found the formula. I wasn't thinking right. By using that formula 6.37x10^3 times Pi equals 2.0000. Than i multiplied it by 2 and got 4.00x10^4.