Chapter 5 Physical Science
The physics of a refrigerator most closely resembles the physics of
a heat engine
A person stands on a very sensitive scale and inhales deeply. The reading on the scale
any of the above, depending
Molecular motion is not responsible for
buoyancy
The working substance (or refrigerant) used in most refrigerators is a
gas that is easy liquefy
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 on the walls
less often
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 a gas can occur by
radiation, convection, conduction
The pressure of the earth's atmosphere at sea level is due to
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 is 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
heat is absorbed by the refrigerant in a refrigerator when it
vaporizes