3] Rotation Curves and the Mass of the Milky Way. a) Measurements of the motion
ID: 155596 • Letter: 3
Question
3] Rotation Curves and the Mass of the Milky Way. a) Measurements of the motion of our Solar System with respect to distant galaxies and quasars have shown that we orbit the center of our Galaxy with a speed of about V = 250 km / second. Astronomers have also found that the center of our Galaxy is located at a distance of 8.5 kilo-parsecs from us. Thus, the distance between the Sun and the Galactic center is 8.5 x 103 pc. A parsec (1 pc) contains 3.086 x 1018 cm. Calculate the circumference of the Sun
Explanation / Answer
Radius of the orbit, R = 8.5*10^3 pC
= 8.5*10^3*3.086*10^18 cm
= 8.5*10^3*3.086*10^18*10^-2 m
= 2.6231*10^20 m
Circumaference = 2*pi*R
= 2*pi*2.6231*10^20
= 1.65*10^21 m <<<<<<<<<--------Answer