Calculating the Mass of the Sun Using Orbital Data and Gravitational Constant G

[8parks11]

a)calculate the mass of the sun from the radiuos of the Earth's orbit (1.5 x 10^11m), the Earth's period in its orbit, and the gravitational constant of G.

Sohere we are given the speedof light, 3x10^8, and G as 6.673x10^-11

so i get that v=2pi x r / T
and that r= ct

how do i continue from then on to get the mass of the sun that is
1.98892 × 10^30 kilograms

 

[8parks11]

how would i use 2pi * r /T = V
then r = ct?

 

[8parks11]

zz help! pleasezz

 

[EthanB]

What are we doing with the speed of light? Stick with summing the forces and you'll be ok.