The sun, which is 2.2 × 1020 m from the center of the milky way galaxy, revolves around that center once every 2.5 × 108 years. assuming each star in the galaxy has a mass equal to the sun’s mass of 2.0 × 1030 the stars are distributed uniformly in a sphere about the galactic center, and the sun is at the edge of that sphere, estimate the number of stars in the galaxy. note: the actual number of stars in the milky way is between 1011 and 4 × 1011 .

Which of the following is the phase that results when the moon is on the opposite side of the earth from the sun? a. quarter moon b. crescent moon c. new moon d. full moon

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?

Adiver named jacques observes a bubble of air rising from the bottom of a lake (where the absolute pressure is 3.50 atm) to the surface (where the pressure is 1.00 atm). the temperature at the bottom is 4.00 ∘c, and the temperature at the surface is 23.0 ∘c.what is the ratio of the volume of the bubble as it reaches the surface (vs) to its volume at the bottom (vb)? if jaques were to hold his breath the air in his lungs would be kept at a constant temperature. would it be safe for jacques to hold his breath while ascending from the bottom of the lake to the surface?