# Star orbiting black hole

Hi
I have to describe a method to solve a problem involving a black hole. The only information given is the period of the orbiting star and the radius of the orbit. I have to find the stars mass.

Would i use the equation F=(mv^2)/r and then substitute in v=(2 pi r)/T for the radius where T is the period? Then would i set the original equation equal to G(Mm/r^2) where the first two masses would cancel out and then solve for the final mass?

Thanks

Related Introductory Physics Homework Help News on Phys.org
rock.freak667
Homework Helper
Equating those two equations, you will only be able to get the mass of the black hole. The star's mass will cancel out.

Equating those two equations, you will only be able to get the mass of the black hole. The star's mass will cancel out.
ok. but the mass i get will be for the star?
thanks

rock.freak667
Homework Helper
ok. but the mass i get will be for the star?
thanks
If the star's mass will cancel out, you will only be left with one mass (and it's not the mass of the star )