In Exercises 5978, solve each equation. Use words or set notation to identify equations that have no solution, or equations that are true for all real numbers. 0.06(x 5) 0.03(2x 7) 0.09

1 Astronomy Unit 4B Milky Way Galaxy Part 2: The Mass of the Galaxy- We can estimate the mass of the galaxy from the sun’s orbital motion Kepler’s 3 Law applied to the Galaxy is: 3 2 o M = galp o Here, a= the distance to the center of the galaxy, 8.5 kpc or 1.75 AU o The orbital period of the sun around the galaxy is the circumference of its orbit, 2pia, divided by its orbital speed of 220 km/s o It takes the sun 240 million years to orbit the galaxy once Kepler’s Law gives: o M =(gal.75 X 10 AU) / (2.4 X 10 yrs) ) M. = 1.0 X 10 M. 11 o The galaxy contains the equivalent of about 100 billion Suns Mass Beyond the S