Which of the following phases has a variable volume?
solid
liquid
gas
all of the above

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?

The mass of a bowling ball is 10 kg and the mass of a ping pong ball is 0.015 kg. if the two objects are 5 meters apart, what is the gravitational force ?