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
