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