Remarkable data indicate the presence of a massive black hole at the center of o
ID: 1902575 • Letter: R
Question
Remarkable data indicate the presence of a massive black hole at the center of our Milky Way galaxy. The W. M. Keck 10 meter diameter telescopes in Hawaii were used by Andrea Ghez and her colleagues to observe infrared light coming directly through the dust surrounding the central region of our galaxy (visible light is multiply-scattered by the dust, blocking a direct view). Stars were observed for several consecutive years to determine their orbits near a motionless center that is completely invisible (
Explanation / Answer
You say that you need help with d) but all I see is c). Is that it? You have radius and mass of the star, you have calculated the tangential speed of the star. I would balance the centrifugal force against the gravitational force. Fcent =Fgrav Mstar * w^2 * R = G * Mstar * Mhole / R w = v / R Mstar * (v / R)^2 * R = G * Mstar * Mhole / R^2 v^2 * R = G * Mhole Mhole = (v ^2* R)/G Mhole = ((1328257 m/s)^2) * (11014 m) / 6.67 x 10^-11 m^3/kg-s^2 Mhole = 2.19 x 10^20 kg (assuming our numbers are correct) Good Luck