Gravitational problem

1. Dec 12, 2007

Demin

1. The problem statement, all variables and given/known data

Whats the earth's orbital period around the sun if mE=5.98x10^24kg , mS =2x10^30kg,
r = 1.5x10^11

2. Relevant equations
T^2= kr^3

3. The attempt at a solution

i can figure out the period easily w/ 2 radii + 1 period

2. Dec 12, 2007

Shooting Star

Assuming that the orbit is circular, use grav force on earth due to sun is equal to the centrpetal force. Also, T=2pi/omega.

3. Dec 12, 2007

Demin

cant use omega ,,answer has to be in sec not rads :(

4. Dec 12, 2007

Shooting Star

That's why I'd given the relation between T and omega.