Deck 16: Heat Transfer

Question 1

Warm air rises because faster-moving molecules tend to move to regions of less

A)density and less pressure.
B)pressure.
C)density.

Answer 1

density and less pressure.

Question 2

Metals are both good heat conductors and good electrical conductors because of the

A)similarity between 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)ability of metals to transfer energy easily.

Answer 2

looseness of outer electrons in metal atoms.

Question 3

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)shows this common knowledge is false.
C)supports or contradicts this common knowledge.

Answer 3

supports this common knowledge.

Question 4

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 5

Substances absorb heat energy by the process of

A)conduction.
B)convection.
C)radiation.
D)all of these

Question 6

The technology for orbiting solar power plants

A)awaits the next century.
B)already exists.
C)is theoretically impossible.

Question 7

If a solid object radiates more energy than it absorbs,its

A)internal energy and temperature decrease.
B)temperature decreases.
C)internal energy decreases.
D)None of the above choices are true.

Question 8

Which body glows with electromagnetic waves?

A)both the Sun and the Earth
B)only the Sun
C)only the Earth
D)neither the Sun or the Earth

Question 9

Energy transfer by convection is primarily restricted to

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

Question 10

The higher the temperature of an object

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

Question 11

A good heat conductor is

A)a poor insulator.
B)a good insulator.
C)neither a poor nor a good insulator.

Question 12

The pupil of your eye is

A)a net absorber of radiant energy.
B)a net emitter of radiant energy.
C)neither a net absorber nor emitter of radiant energy.

Question 13

Objects that radiate relatively well

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

Question 14

An object will normally be a net radiator of energy when its temperature is

A)higher than its surroundings.
B)lower than its surroundings.
C)neither of these

Question 15

If air were a better conductor than it is,at nighttime the Earth would be

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

Question 16

Cold water will warm to room temperature faster in a

A)black pot.
B)silver pot.
C)depends more on the size of the pots than their color

Question 17

Your feet feel warmer on a rug than on a tile floor because a rug

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

Question 18

At the same temperature,which move with the greater speed in the air?

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

Question 19

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

A)black pot.
B)silver pot.
C)red pot.
D)depends more on the size of the pot than its color

Question 20

The planet Earth loses heat mainly by

A)conduction.
B)convection.
C)radiation.
D)all of these

Question 21

When a volume of air is compressed,its temperature

A)increases.
B)decreases.
C)neither increases nor decreases.

Question 22

Both black and white road surfaces absorb sunlight.At the end of a sunny day the warmer road surface will be

A)the black surface.
B)the white surface.
C)Neither - there is no difference.

Question 23

Use the following figure to answer the question:
A Thermos bottle has double glass walls with silver coating on the glass surfaces that face one another.The silver coating reduces the energy that is transferred by

A)conduction.
B)convection.
C)radiation.
D)friction.
E)none of these

Question 24

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 25

A good absorber of radiation is a

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

Question 26

If a volume of air is warmed,it expands.If a volume of air expands,it

A)warms.
B)cools.
C)neither warms nor cools.

Question 27

Newton's law of cooling applies to objects that are

A)cooling.
B)heating.
C)both of these
D)none of these

Question 28

Suppose you are served coffee at a restaurant before you are ready to drink it.In order for it to be the hottest when you are ready for it,you should add cream

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

Question 29

Suppose you want to save energy and you're going to leave your warm house for a half hour on a cold day.You should turn the thermostat

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

Question 30

An object will normally be a net radiator of energy when its internal energy is

A)more than that of its surroundings.
B)less than that of its surroundings.
C)neither of these,because internal energy is not temperature.

Question 31

Double the absolute temperature of helium gas and the average speed of its molecules

A)less than doubles.
B)doubles.
C)more than doubles.

Question 32

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 33

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 will have the same average speed at the same temperature.

Question 34

One of the main reasons one can walk barefoot on red-hot coals of wood without burning the feet has to do with

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

Question 35

Both black and white road surfaces radiate energy.At the end of a starry night the warmer road surface will be

A)the black surface.
B)the white surface.
C)Neither - there is no difference.

Question 36

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

Question 37

If molecules in a gas sample moved so they completely missed each other,the gas's temperature would

A)increase.
B)decrease.
C)stay the same.

Question 38

Use the following figure to answer the question:
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.

Question 39

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 these

Question 40

The reason the sun's radiant energy is of shorter wavelengths than the Earth's is because the sun

A)has much more internal energy.
B)has a higher temperature than the Earth.
C)is an energy source while the Earth is primarily an energy receiver.
D)all of these
E)none of these

Question 41

Suppose you want to save energy and you're going to leave your cool house for a half hour on a hot day.You should turn the temperature setting on the air conditioner

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