2 - Chapter 5 PHYS

A person stands on a very sensitive scale and inhales deeply. The reading on the scale

depends on how the expansion of the person's chest compares with the volume of air inhaled

In any process, the maximum amount of heat that can be converted to mechanical energy

depends on the intake and exhaust temperatures

The temperature of a gas sample in a container of fixed volume is raised. The gas exerts a higher pressure on the walls of its container because its molecules

have higher average velocities and strike the walls more often

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

A refrigerator gives off

more heat than it absorbs from its contents

Buoyancy occurs because, as the depth in a fluid increases, the fluid's

pressure increases

The fluid at the bottom of a container is

radiation and convection only

Heat transfer in a vacuum can occur by

radiation only

Heat transfer in a gas can occur by

radiation, convection, and conduction

An ice cube whose center consists of liquid water is floating in a glass of water. When the ice melts, the level of water in the glass

remains the same

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 second law of thermodynamics does not lead to the conlcusion that

the total amount of energy in the universe, including rest energy, is constant

Heat is absorbed by the refrigerant in a refrigerator when it

vaporizes

Oxygen boils at - 183 C. The Fahrenheit equivalent of this temperature is

- 297 F

A frictionless heat engine can be 100 percent efficient only if its exhaust temperature is

0 K

The Celsius equivalent of a temperature of 120 F is

49 F

Molecular motion is not responsible for

Buoyancy

True/False: All molecules have the same size and mass.

False.

The physics of a refrigerator most closely resembles the physics of

a heat engine

One gram of steam at 100 C causes a more serious burn than 1 g of water at 100 C because the steam

contain more energy

The working substance (or refrigerant) used in most refrigerators is a

gas that is easy to liquify

In any process, the maximum amount of mechanical energy that can be converted to heat

is 100 percent

The density of freshwater is 1.00 g/cm^3 and that of seawater is 1.03 g/cm^3. A ship will float

lower in freshwater than in seawater

Two thermometers, one calibrated in F and the other in C, are used to measure the same temperature. The numerical reading on the Fahrenheit thermometer

may be any of these, depending on the temperature

Absolute zero may be regarded as that temperature at which

molecular motion in a gas would be the minimum possible

A heat engine takes in heat at one temperature and turns

some of it into work and rejects the rest at a lower temperature