Which describes the molecular motion of a planet?

a.
the up and down and back and forth motion of the atoms that make up the planet as they collide with the atmosphere

b.
the constant up and down and back and forth motion of the atoms that make up the planet

c.
the transfer of atoms from the top of the planet to the center of the planet in response to gravity

Ways that industry and agriculture use physical properties to separate substances

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.

Why does gravity have a lesser than grater effect on higher altitudes?