Ok I remeber a question on my physics test. where theres a planet orbiting a star in some other solar system. heres what was given to me. the radius,and the time it took for it to finish 1 revolution. I was asked to find the mass of the sun, that the planet was orbiting around so heres what i did. I calculated the distance, which was 2 pi r. I divided that value by time and got the speed. then i used Fc=FG formula. mv^2/r = Gm1m2/r^2 with some cancellations, im left with v^2=Gm(star)/r so i just isolated for m and solved it. I remember i got like some number x 10^30kg. but did i do this question right? was this the right method of solving it?