By using observations of the Doppler Shift of radiation coming from ionized gas in the nucleus of a galaxy, it is determined that the gas orbits the nucleus at a speed of 3000 km/s (convert to m/s) at a distance from the center of 20 light-years (convert to meters). Calculate the amount of mass within 20 light-years of the galaxy's center (in kilograms and solar masses). Make sure you show all parts of your solution and don't forget units. By using observations of the Doppler Shift of radiation coming from ionized gas in the nucleus of a galaxy, it is determined that the gas orbits the nucleus at a speed of 3000 km/s (convert to m/s) at a distance from the center of 20 light-years (convert to meters). Calculate the amount of mass within 20 light-years of the galaxy's center (in kilograms and solar masses). Make sure you show all parts of your solution and don't forget units.