Physical Science Chapter 5
The physics of a refrigerator most costly resembles the physics of
a heat engine
Molecular motion is not responsible for
buoyancy
a person stands on a very sensitive scale and inhales deeply
depending on how the expansion of the person's chest compares with the volume of air inhaled
the working substance (or refrigerant) used in most refrigerators is a
gas that is easy to liquefy
When a vapor condenses into a liquid,
it gives off heat
at constant pressure, the volume of a gas sample is directly proportional to
its absolute temperature
on the molecular level, heat is
kinetic energy
The volume of a gas sample is increased while its temperature is held constant. The gas exerts a lower pressure on the walls of its container because its molecules strike the walls
less often
Heat is absorbed by the refrigerant in a refrigerator when it
melts
Absolute zero may be regarded as that temperature at which
molecular motion in a gas would be the minimum
a refrigerator gives off
more heat than it absorbs from its contents
Heat transfer in a vacuum can occur by
radiation only
Heat transfer in gas can occur by
radiation, convection, and conduction
The pressure of the earth's atmosphere at sea level is due to atmosphere
the gravitational attraction of the earth for the atmosphere
Food cooks more rapidly in a pressure cooker than in an ordinary pot with a loose lid because
the high pressure raises the boiling point of water
The greater the entropy of a system of particles
the less the order of the system
at a given temperature
the molecules in a gas all have the same average energy
When evaporation occurs, the liquid that remains to cooler because
the slowest molecules remain behind
The fluid at the bottom of a container is
under more pressure than the fluid at the top