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Star orbiting black hole

  • #1
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
 

Answers and Replies

  • #2
rock.freak667
Homework Helper
6,230
31
Equating those two equations, you will only be able to get the mass of the black hole. The star's mass will cancel out.
 
  • #3
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
 
  • #4
rock.freak667
Homework Helper
6,230
31
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 :wink:)
 

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