Deck 16: Heat Transfer

Question 1

Because of trapped air inside, snow is a

A)good conductor.
B)good insulator.
C)both a good insulator and a poor conductor.
D)none of the above

Answer 1

both a good insulator and a poor conductor.

Question 2

Which of these are good conductors?

A)feathers.
B)wood.
C)snow.
D)all the above
E)none of the above

Answer 2

none of the above

Question 3

A water-filled paper cup held in a flame will not catch fire. This is because

A)the inside of the paper is wet.
B)water is an excellent conductor of heat.
C)paper is a poor conductor of heat.
D)the paper cup cannot become appreciably hotter than the water it contains.

Answer 3

the paper cup cannot become appreciably hotter than the water it contains.

Question 4

In terms of transferring heat, red-hot wooden coals

A)conduct quite well.
B)conduct poorly.
C)radiate poorly.
D)convect poorly.

Question 5

Soaring birds and glider pilots can remain aloft for hours without expending power, due to

A)conduction.
B)convection.
C)radiation.
D)all of the above

Question 6

You can safely hold your fingers on both sides of a candle flame due mainly to

A)conduction.
B)convection.
C)radiation.
D)none of the above

Question 7

A good heat conductor is

A)a poor insulator.
B)a good insulator.
C)neither of these

Question 8

If a volume of air is warmed, it expands and tends to

A)warm.
B)cool.
C)neither of these

Question 9

When you touch a nail stuck in ice, energy flows from

A)the ice to your hand.
B)your hand to the ice.
C)both of these
D)neither of these

Question 10

A block of wood and a block of copper will feel neither hot nor cold to the touch when they each have

A)equal temperatures.
B)your temperature.
C)equal conductivities.
D)none of the above

Question 11

Metals are good conductors of both heat and electricity due to

A)similar thermal and electrical conductive properties.
B)looseness of outer electrons in metal atoms.
C)relatively high densities of metals.
D)high elasticity of metals.
E)both transferring energy easily.

Question 12

A bare roof on a warmly heated home on a snowy day indicates

A)an unwanted flow of heat
B)poor insulation.
C)fairly good conductivity.
D)all of the above

Question 13

On a cold day your feet feel warmer on a rug than on a tile floor because a rug

A)is usually warmer than tile.
B)is a poorer conductor.
C)for the same mass has more internal energy than tile.
D)all of the above
E)none of the above

Question 14

Energy transfer by convection is primarily restricted to

A)solids.
B)liquids.
C)gases.
D)fluids.
E)none of the above

Question 15

The reason you can walk barefoot on red-hot coals of wood without burning your feet mainly involves

A)low temperature of the coals.
B)low conductivity of the coals.
C)mind over matter techniques.

Question 16

If you were caught in freezing weather with only a candle for heat, you would be warmer in

A)an igloo.
B)a tent.
C)a wooden house.
D)a car.

Question 17

Wood is a poor conductor

A)when it is cold.
B)at common room temperature.
C)when it is hot.
D)all of the above
E)none of the above

Question 18

In practice, a good insulator

A)stops heat flow.
B)slows heat flow.
C)speeds negative heat flow.
D)all of the above

Question 19

If air were a better conductor, at nighttime Earth would be

A)considerably colder.
B)considerably warmer.
C)not appreciably different in temperature.

Question 20

Which of these are good insulators?

A)feathers.
B)wood.
C)snow.
D)all the above
E)none of the above

Question 21

The lower the temperature of an object, the

A)lower the frequency of radiation it emits.
B)longer the wavelengths it radiates.
C)both of these
D)neither of these

Question 22

Terrestrial radiation is

A)emitted by Earth.
B)emitted by the Sun.
C)both of these
D)neither of these

Question 23

When an object absorbs as much as it radiates

A)it remains at about the same temperature.
B)it is a net absorber.
C)it is a net radiator.
D)none of the above

Question 24

The form of heat transfer that doesn't depend on a medium is

A)conduction.
B)convection.
C)radiation.
D)all of the above

Question 25

A parcel of warmed air rises due to

A)random molecular motion.
B)radiation.
C)buoyancy.
D)increased energy of its molecules.

Question 26

When a volume of air is compressed, air temperature

A)increases.
B)decreases.
C)neither of these

Question 27

The pupil of your eye is a net

A)absorber of radiant energy.
B)emitter of radiant energy.
C)reflector of radiant energy.
D)none of the above

Question 28

Steam that issues from a pressure cooker

A)is invisible.
B)cools as it expands.
C)both of these
D)neither of these

Question 29

Molecules in a region of expanding air more often collide with neighboring molecules that are

A)approaching.
B)receding.
C)nearly out of range.

Question 30

If you release a single molecule in an evacuated region it will initially

A)fall just as a baseball would.
B)move in any direction.
C)convect upward.
D)be buoyed upward.
E)none of the above

Question 31

A region of expanding air tends to

A)cool.
B)warm.
C)both of the these
D)neither of these

Question 32

At the same temperature, which has greater average speed in the air?

A)very light molecules
B)heavier molecules
C)both have equal average speeds.

Question 33

If a pizza absorbs more energy than it emits, its temperature

A)decreases.
B)is unaffected.
C)increases.
D)none of the above

Question 34

Sun's radiant energy is composed of shorter wavelengths than Earth's due to Sun's greater

A)size.
B)surface temperature.
C)both of these
D)neither of these

Question 35

The higher the temperature of an object, the

A)longer the wavelengths it radiates.
B)shorter the wavelengths it radiates.
C)makes no difference in the wavelengths it radiates

Question 36

In a mixture of hydrogen gas, oxygen gas, and nitrogen gas, the molecules with the greatest average speed are those of

A)hydrogen.
B)oxygen.
C)nitrogen.
D)all the same

Question 37

Blow on your hand with your mouth open. Then do the same with your lips puckered and you'll find

A)a difference in temperatures.
B)the breath from puckered lips is cooler.
C)both of these
D)neither of these

Question 38

If no molecular collisions occurred in a sample of gas, temperature of the gas would

A)increase.
B)decrease.
C)be unaffected.

Question 39

If a pizza radiates more energy than it absorbs, its temperature

A)decreases.
B)is unaffected.
C)increases.
D)none of the above

Question 40

Objects that radiate relatively well

A)absorb radiation relatively well.
B)reflect radiation relatively well.
C)both of these
D)neither of these

Question 41

A photovoltaic cell receives energy input by

A)conduction.
B)convection.
C)radiation.
D)all of the above

Question 42

Both black and white road surfaces radiate energy. At midnight on a starry night the warmer road surface is the

A)black surface.
B)white surface.
C)neither, as no noticeable difference.

Question 43

A good absorber of radiation is a

A)good emitter of radiation.
B)poor emitter of radiation.
C)good reflector.
D)none of the above

Question 44

If a poor absorber of radiation were a good emitter, its temperature would be

A)less than its surroundings.
B)more than its surroundings.
C)the same as its surroundings.

Question 45

A liter of hot water will cool to room temperature faster in a

A)black pot.
B)silver pot.
C)red pot.
D)none of the above

Question 46

A bridge is more likely to be ice covered than the roadway on a cold day because

A)a bridge is more conducting than ground.
B)a bridge is more commonly wet than ground.
C)heat upwelling from the ground below is absent on a bridge.
D)none of the above

Question 47

An apple pie will be a net emitter of energy when its temperature is

A)higher than its surroundings.
B)lower than its surroundings.
C)none of these

Question 48

Newton's law of cooling applies to objects undergoing

A)cooling.
B)warming.
C)both of these
D)neither of these

Question 49

The planet Earth loses heat primarily by

A)conduction.
B)convection.
C)radiation.
D)all of the above

Question 50

The temperature of outer space is

A)zero.
B)about 2.7 kelvin.
C)meaningless.
D)none of the above

Question 51

A red-hot piece of coal will cool quicker in a

A)cold room.
B)warm over.
C)both the same.

Question 52

Glass in a florist's greenhouse acts as a one-way valve in that it

A)lets light energy flow only in one direction.
B)cuts off unwanted radiation.
C)allows high-frequency waves in and blocks low-frequency waves exiting.
D)is transparent only to lower-frequency waves.

Question 53

Which body glows with electromagnetic waves?

A)the Sun
B)the Earth
C)you and your classmates
D)all of the above

Question 54

When you're ready for the hottest sips of coffee, add cream

A)right away.
B)at any time.
C)when you are ready to drink the coffee.

Question 55

A blueberry pie will be a net absorber of energy when its temperature is

A)higher than its surroundings.
B)lower than its surroundings.
C)none of these

Question 56

A liter of cold water will warm faster in sunlight in a

A)black pot.
B)silver pot.
C)red pot.
D)none of the above

Question 57

Waves emitted by the Sun and terrestrial wave emissions are

A)the same except for their frequencies and wavelengths.
B)entirely different kinds of waves.
C)identical.

Question 58

Both black and white road surfaces absorb sunlight. The warmer road surface at the end of a sunny day is the

A)black surface.
B)white surface.
C)neither of these

Question 59

A good reflector of radiation is a

A)good absorber of radiation.
B)good emitter of radiation.
C)poor absorber of radiation.
D)none of the above

Question 60

It is commonly thought that a can of beverage will cool faster in the coldest part of a refrigerator. Knowledge of Newton's law of cooling

A)supports this common knowledge.
B)contradicts this common knowledge.
C)is unrelated to this common knowledge.

Question 61

Heat normally flows from objects of high

A)internal energy to objects of low internal energy.
B)temperature to objects of low temperature.
C)both of these
D)neither of these

Question 62

When coal dust is spread on snow on a sunny day

A)more melting occurs.
B)less melting occurs.
C)no change in melting rate occurs.

Question 63

Which is the most abundant greenhouse gas in Earth's atmosphere?

A)nitrogen.
B)water vapor.
C)carbon dioxide.
D)none of the above

Question 64

The solar constant for Earth is

A)0.7 kW/m².
B)1.0 kW/m².
C)1.4 kW/m².
D)more than 1.4 kW/m².

Question 65

The amount of solar energy per square meter atop the atmosphere at right angles to the Sun's rays is about

A)700 joules.
B)1000 joules.
C)1400 joules.
D)much more than 1400 joules.

Question 66

A Thermos bottle has double glass walls with silver coating on the glass surfaces that face each other. The silver coating reduces energy transfer by

A)conduction.
B)convection.
C)radiation.
D)all the above
E)none of the above

Question 67

Long ago a runaway greenhouse effect transformed the planet

A)Mercury.
B)Venus.
C)Mars.
D)all of the above

Question 68

Every equation in physics reminds us of a lesson: we can never change only one thing. When we change the composition of the atmosphere we likely also change

A)its transparency.
B)its reflectivity.
C)its average temperature.
D)Earth's climate.
E)all of the above

Question 69

Solar power is used in many parts of the world for

A)heating water.
B)generating electricity.
C)both of these
D)neither of these

Question 70

To save energy while you leave your warm house for a half hour on a cold day, turn the thermostat

A)down.
B)up.
C)to room temperature.

Question 71

Solar power is the rate at which

A)the Sun emits energy.
B)solar energy is received from the Sun.
C)the atmosphere absorbs energy.
D)all of the above
E)none of the above

Question 72

If there were no greenhouse effect, Earth's average temperature would likely be

A)near absolute zero.
B)a frigid -18°C.
C)comfortably cooler.
D)warmer than now.

Question 73

If the composition of the upper atmosphere were altered to permit a greater amount of terrestrial radiation to escape, Earth would be

A)cooler.
B)warmer.
C)quite unaffected.
D)none of the above

Question 74

The heat we enjoy on a sunny day is due mainly to the Sun's

A)high surface temperature.
B)relatively close distance.
C)enormous size.
D)none of the above

Question 75

To save energy while you leave your cool house for a half hour on a hot day, turn the temperature setting on the air conditioner

A)down.
B)up.
C)off altogether.
D)to room temperature.

Question 76

Looking forward, common consensus will likely agree that the wisest use of fossil fuels is to

A)convert them to heat and smoke.
B)save them for tomorrow's materials.
C)extract and sell them as quickly as possible.
D)all of the above

Question 77

When a hot object makes thermal contact with a cold object, the direction of

A)temperature is from hot to cold.
B)internal energy flow is from hot to cold
C)both of these
D)neither of these

Question 78

The solar constant is the

A)input of solar energy per square meter atop Earth's atmosphere.
B)difference between solar energy atop the atmosphere and that reaching ground.
C)maximum amount of energy Earth receives from the Sun.

Question 79

Substances absorb heat energy by the process of

A)conduction.
B)convection.
C)radiation.
D)all of the above

Question 80

Hydrogen and oxygen molecules in a sample of gas have the same temperature. This means the hydrogen molecules, on average, have the same

A)speed and the same kinetic energy.
B)speed, but more kinetic energy.
C)speed, but less kinetic energy.
D)kinetic energy, but more speed.
E)kinetic energy, but less speed.