posted by Scooby10 .
Astronomers have a mathematical model for the orbital speed of the stars as a function of their distance x from the center of the galaxy: V(x) = 350x/(1+(x^2))^(3/4) where x = 1 for 10,000 light years, x = 2 for 20,000 light years. At a distance of 10,000 light years, the rotational speed is v(1)= 208 km/sec. The radius of the galaxy M-101 is about 90,000 light years. How fast are stars at this radius orbiting the center?