Chapter 2 Flashcards
If you double the energy content of a kilogram of gas, the temperature of the gas (measured on the absolute K scale)
a. is unchanged
b. increases by the square-root of 2
c. doubles
d. is multiplied by 4
c. doubles
About how fast are molecules in air moving?
a. 1000 ft/sec - speed of sound
b. the speed of light
c. 9.8 m/s
d. 9.8 cm/sec
a. 1000 ft/sec - speed of sound
Temperature is the measure of
a. average momentum
b. average kinetic energy
c. average velocity
d. average total energy
b. average kinetic energy
in a bucket of water, the instantaneous speed of the molecules is closet to
a. zero, since they dont move
b. whatever speed the wood is moving
c. approximately 1.7 meters per second
d. approximately 1000 feet per second
e. approximately 186,000 miles per second
d. approximately 1000 feet per second
A refrigerator operating in a room
a. warms the room
b. cools the room
c. has no effect on the room
d. removes water vapor from the room
a. warms the room
A refrigerator with its “door open” is operating in a room. it
a. warms the room
b. cools the room
c. has no effect on the room
d. removes water vapor from the room
a. warms the room
A table has the same temperature as the air above it. That means that the molecules in the air and in the table have
a. the same average velocity
b. the same average energy
c. the same average acceleration
d. the same average mass
b. the same average energy
Ice melts at
a. 0 k
b. 0 c
c. 0 f
d. 100 c
b. 0 c
A gas heater warms a room mostly through
a. convection
b. conduction
c. radiation
d. depletion
a. convection
The velocity of sound
a. increases when the temperature increases
b. decreases when the temperature increases
c. depends on the pressure of the air
d. is constant, independent of the temperature
a. increases when the temperature increases
If a gasoline engine produces a hotter explosion, then the efficiency of the engine should
a. be the same
b. go up
c. go down
b. go up
A cup full of cold water and amde of plastic feels warmer than one made of glass because
a. plastic is warmed by water
b. plastic conducts heat less than glass
c. plastic conducts heat better than glass
d. plastic dissolves in water
b. plastic conducts heat less than glass
The atom with the fewest number of protons is
a. helium
b. carbon
c. hydrogen
d. oxygen
c. hydrogen
How many atoms are there in the width of a human hair? about
a. 25
b. 125,000
c. 273,000,000,000
d. 6 x 10^23
b. 125,000
The speed of sound is approximately
a. 1 foot per nanosecond
b. 1 foot per second
c. 1000 feet per second
d. 186,000 miles per hour
c. 1000 feet per second
Put a hot glass in cool water. The glass shatters because
a. it heats the surface water to boiling
b. the outer surface of the glass contracts rapidly, but the inner part doesn’t
c. the outer surface of the glass expands rapidly
d. the rapid conduction of heat triggers strong vibrations
b. the outer surface of the glass contracts rapidly, but the inner part doesn’t
Sea level is rising from global warming. The main cause is
a. expanding sea water
b. melting glaciers
c. expanding rock under the sea
d. contracting earth (while the water stays constant)
a. expanding sea water
The temperature warms by 2 C that is approximately the same as
a. 1 f
b. 2 f
c. 4 f
d. 1/2 f
c. 4 f
Heat a room using the least energy by
a. burning natural gas (methane)
b. using natural gas to run a heat pump
c. burning coal
d. burning gasoline
b. using natural gas to run a heat pump
There is almost no hydrogen gas in the atmosphere because
a. it escapes the earths, gravity
b. there is very little hydrogen in the oceans or land
c. hydrogen molecules move slower than oxygen and nitrogen
d. hydrogen has all sunk to the earths core
a. it escapes the earths, gravity
At mach 10, if all the energy of a meteorite went into heating the meteorite, its temperature would be about
a. 300 c
b. 6000 c
c. 30,000 c
d. 100,000 c
c. 30,000 c
The New Orleans levees failed because
a. thermal expansion broke them
b. they were made of continuous concrete that could not stand the pressure
c. they had leaks at the thermal expansion joints
d. they were weaker at the thermal expansion joints
d. they were weaker at the thermal expansion joints
If temperature rises by 5 C = 9 F, then the rise in sea level will be about
a. 2 inches
b. 2 feet
c. 12 feet
d. 97 feet
b. 2 feet
For a typical auto, the fraction of the gasoline energy wasted as heat is about (careful could be trick question)
a. 1 %
b. 10 %
c. 20 %
d. 80 %
d. 80 %
The temperature in the sun
a. is always hotter than in the shade
b. is always the same as in the shade
c. is sometimes cooler than in the shade
d. is not well defined
d. is not well defined
When a material is cooled
a. it stays the same size
b. it contracts.
c. it expands
d. some materials contract and some expand
d. some materials contract and some expand
The melting temperature of an object is usually
a. equal to its freezing point
b. higher than the freezing point
c. lower than the freezing point
d. equal to the boiling point
a. equal to its freezing point
Absolute zero is the temperature of
a. frozen water
b. the universe
c. liquid helium
d. nothing
d. nothing
When a liquid boils, the increase in volume (liquid to gas) is typically a factor of
a. 10
b. 100
c. 1000
d. 1,000,000
c. 1000
If the temperature of a gas in a container goes from 0 C to 300 C, the pressure will
a. stay the same
b. double
c. become 300 times greater
d. become infinite
b. double
Fire walking is similar to
a. water on a saucepan
b. the space shuttle reentry
c. an automobile air bag
d. water skiing
a. water on a saucepan
For gasoline to explode, it needs
a. to be mixed with oxygen
b. to be mixed with nitrogen
c. to be mixed with carbon dioxide
d. no mixing need, just a spark
a. to be mixed with oxygen
To be more efficient, the temperature difference (between the ignited hot fuel and the cool part of the engine) should be
a. as small as possible
b. as large as possible
c. it doesn’t matter
b. as large as possible
Heat flow through empty space (no atoms present)
a. is impossible
b. occurs through conduction
c. occurs through convection
d. occurs through radiation
d. occurs through radiation
Entropy (optional topic) measures
a. heat
b. temperature
c. disorder
d. energy
c. disorder
Molecular motion stops at
a. 0 K
b. 0 C
c. 0 F
d. 32 F
a. 0 K
