What is a galaxy? how many galaxies are there and how many stars does each galaxy hold?

A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. Scientists estimate that there are 200 billion to 400 billion — yes, that's billion with a “b" — stars in the Milky Way galaxy. Our Milky Way galaxy is just one of the many galaxies in our universe.

Answerthe force between the charges will be  f/9 (one-ninth of force f)explanationcoulomb's law relates the magnitudes  two point charges q₁ and q₂, the distance, r, between the charges, and the electrostatic force, f, between the two charges:     k represents coulomb's constant, k = 8.99×10⁹ n·m²/c².note that if we have r = 3r, then   

Answer(b) both involve the use of levers;