- #1
Antepolleo
- 40
- 0
I'm having a little bit of a problem with this one. Here's the question:
X-ray pulses from Cygnus X-1, a celestial x-ray source, have been recorded during high-altitude rocket flights. The signals can be interpreted as originating when a blob of ionized matter orbits a black hole with a period of 4.7 ms. If the blob were in a circular orbit about a black hole whose mass is 18 * MSun, what is the orbit radius?
Here's my train of thought. I used one of Kepler's laws:
[tex]
\begin{equation*}
\begin{split}
T^2 = \frac{4\pi^2r^3}{GM_{blackhole}}\\
r = (\frac{T^2GM_{blackhole}}{4\pi^2})^(\frac{1}{3})\\
\end{split}
\end{equation*}
[/tex]
I changed the milliseconds to seconds, and I got a answer of 110196.285 meters. I'm letting the mass of the sun be 1.991 x 1030 kg.
I enter this into webassign, but I doesn't like it. What am I doing wrong?
X-ray pulses from Cygnus X-1, a celestial x-ray source, have been recorded during high-altitude rocket flights. The signals can be interpreted as originating when a blob of ionized matter orbits a black hole with a period of 4.7 ms. If the blob were in a circular orbit about a black hole whose mass is 18 * MSun, what is the orbit radius?
Here's my train of thought. I used one of Kepler's laws:
[tex]
\begin{equation*}
\begin{split}
T^2 = \frac{4\pi^2r^3}{GM_{blackhole}}\\
r = (\frac{T^2GM_{blackhole}}{4\pi^2})^(\frac{1}{3})\\
\end{split}
\end{equation*}
[/tex]
I changed the milliseconds to seconds, and I got a answer of 110196.285 meters. I'm letting the mass of the sun be 1.991 x 1030 kg.
I enter this into webassign, but I doesn't like it. What am I doing wrong?