chapter15&16

Question 1

When we speak about heat we refer to ___________.

Answer 1

energy in transit

Question 2

In which direction does heat flow spontaneously between hot and cold objects?

Answer 2

From high temperature to low temperature

Question 3

How is heat similar to and different from internal energy?

Answer 3

They are both forms of energy, but heat flows, whereas internal energy does not

Question 4

Does a hot object contain internal energy or does it contain heat?

Answer 4

Internal energy

Question 5

The air in your room is composed of molecules that have

Answer 5

a wide variety of speeds

Question 6

Temperature is most closely related to molecular

Answer 6

kinetic energy

Question 7

Which temperature scales have equal sized degrees?

Answer 7

Celsius and Kelvin

Question 8

When you touch a cold piece of ice with your finger, energy flows

Answer 8

from your finger to the ice.

Question 9

Heat energy travels from an object with a high

Answer 9

temperature to an object with a lower temperature

Question 10

Hot sand cools off faster at night than plants and vegetation. This indicates that the specific heat capacity for sand is ___________.

Answer 10

less than that of plants

Question 11

Does a substance that heats up quickly have a high or a low specific heat capacity?

Answer 11

A low specific heat capacity

Question 12

How does the specific heat capacity of water compare with the specific heat capacities of other common materials?

Answer 12

Water has a higher specific heat capacity than most common materials

Question 13

Why do substances expand when their temperature is increased?

Answer 13

Higher-temperature substances have greater molecular motion

Question 14

Why is ice less dense than water?

Answer 14

Ice crystallizes with an open structure, and the gaps that form between the water molecules in ice increase its volume.

Question 15

Why does all the water in a lake have to be cooled to 4°C before the surface water can be cooled below 4°C?

Answer 15

When water is cooled to 4°C, it sinks and deeper, warmer, water rises to the surface

Question 16

When you touch a hot potato with your finger, energy flows

Answer 16

from the potato to your finger

Question 17

The amount of heat needed to raise the temperature of 1 gram of water by 1°C is

Answer 17

4.19 Joules

Question 18

When 10 grams of hot water cool by 1°C, the amount of heat given off is

Answer 18

41.9 Joules

Question 19

Pour a liter of water at 40°C into a liter of water at 20°C and the final temperature of the two becomes

Answer 19

at or about 30°C.

Question 20

Pour two liters of water at 40°C into one liter of water at 20°C and the final temperature of the two becomes

Answer 20

more than 30°C

Question 21

A substance with a high thermal inertia has a high

Answer 21

specific heat capacity

Question 22

Materials composed of molecules that absorb large amounts of energy in the form of internal vibrations and rotations have

Answer 22

high specific heats

Question 23

Aluminum has a higher specific heat capacity than iron. This means that for equal masses of aluminum and iron, the metal that heats more quickly when the same amount of heat is applied is

Answer 23

iron

Question 24

A substance that cools down faster than others has a

Answer 24

low specific heat capacity

Question 25

A substance that heats up relatively slowly has a

Answer 25

high specific heat capacity

Question 26

When most substances are heated, molecules inside move faster and take up more space, resulting in thermal

Answer 26

expansion

Question 27

When an iron ring is heated, the hole becomes

Answer 27

larger

Question 28

Due to the presence of ice crystals in nearly frozen liquid water, the density of water is

Answer 28

lower

Question 29

If you wish to expand the volume of a sample of water at 4°C

Answer 29

- lower its temperature a bit | - raise its temperature a bit

Question 30

When water at 4°C is heated it expands. If it is instead cooled it will

Answer 30

also expands

Question 31

Before ice can form on a lake, all the water in the lake must be cooled to

Answer 31

4°C

Question 32

If you touch the metal sides in an oven with your bare hand, you're in trouble. But hold your hand briefly in the oven air and you're okay. What does this tell you about the relative conductivities of metal and air?

Answer 32

Metal is a good conductor of heat, whereas air is a terrible conductor of heat

Question 33

Why are materials such as wood, fur, feathers, and even snow good insulators?

Answer 33

Outer electrons in these materials are firmly attached

Question 34

Does a good insulator prevent heat from escaping or slow its passage?

Answer 34

Insulators slow the passage of heat

Question 35

Why does the direction of coastal winds change from day to night?

Answer 35

The specific heat of water is greater than the specific heat of land. Water cools more slowly at night. The temperature difference drives convection and offshore winds.

Question 36

Heat travels from the Sun to Earth by the process of _________.

Answer 36

radiation

Question 37

Relatively speaking, do high-frequency waves have long wavelengths or short wavelengths? Name an electromagnetic wave with higher frequency than blue light.

Answer 37

short, ultraviolet

Question 38

How does the peak frequency of radiant energy relate to the absolute temperature of the radiating source?

Answer 38

The peak frequency increases as temperature increases

Question 39

What is terrestrial radiation?

Answer 39

Terrestrial radiation is infrared radiation emitted by Earth's surface

Question 40

Since all objects emit energy to their surroundings, why don't the temperatures of all objects continuously decrease?

Answer 40

Objects that are good emitters are equally good absorbers, so they absorb radiation as well as emit it

Question 41

What determines whether an object is a net absorber or a net emitter of radiant energy at a given time?

Answer 41

It is determined by the temperature of the object relative to its surroundings. Hotter objects are net emitters

Question 42

Which will normally warm faster: a black pot of cold water or a silvered pot of cold water? Which will cool faster?

Answer 42

black, black

Question 43

Can an object be both a good absorber and a good reflector at the same time?

Answer 43

No. A good absorber reflects very little light

Question 44

What type of gas absorbs and re-emits infrared radiation?

Answer 44

greenhouse gases

Question 45

Newton's law of cooling applies to objects that undergo _________.

Answer 45

cooling or warming

Question 46

Which will undergo the greater rate of cooling: a red-hot poker in a warm oven or a red-hot poker in a cold room (or do both cool at the same rate)?

Answer 46

The poker in the cold room cools fastest.

Question 47

Metals are good conductors of both heat and electricity due to

Answer 47

looseness of outer electrons in metal atoms

Question 48

Which of these are good insulators?

Answer 48

- feathers. - snow. - wood.

Question 49

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

Answer 49

is a poorer conductor

Question 50

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

Answer 50

your temperature

Question 51

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

Answer 51

an igloo

Question 52

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

Answer 52

low conductivity of the coals

Question 53

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

Answer 53

radiation

Question 54

The higher the temperature of an object, the

Answer 54

shorter the wavelengths it radiates

Question 55

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

Answer 55

decreases

Question 56

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

Answer 56

higher than its surroundings.

Question 57

Which body glows with electromagnetic waves?

Answer 57

- the Earth - you and your classmates - the Sun

Question 58

Waves emitted by the Sun and terrestrial wave emissions are

Answer 58

the same except for their frequencies and wavelengths.

Question 59

Long ago a runaway greenhouse effect transformed the planet

Answer 59

venus

Question 60

When coal dust is spread on snow on a sunny day

Answer 60

more melting occurs

Question 61

Heat normally flows from objects of high

Answer 61

temperature to objects of low temperature

Question 62

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

Answer 62

radiation

Question 63

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

Answer 63

internal energy flow is from hot to cold

Question 64

The amount of heat needed to raise the temperature of 1 g of water by 1°C is ___________.

Answer 64

1 calorie

Question 65

If the temperature of a sample of water at 0°C is slightly increased, its volume

Answer 65

decreases

Question 66

If the temperature of a sample of water at 4°C is slightly increased, its volume

Answer 66

increases

Question 67

If the temperature of a sample of water at 4°C is slightly lowered, its volume

Answer 67

increases

Question 68

If you measure the width of an outdoor barn with a steel tape on a very cold day, your measured width will be

Answer 68

a bit long

Question 69

The lower the temperature of an object, the

Answer 69

- lower the frequency of radiation it emits. | - longer the wavelengths it radiates

Question 70

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

Answer 70

black pot

Question 71

In practice, a good insulator

Answer 71

slows heat flow

Question 72

When an object absorbs as much as it radiates

Answer 72

it remains at about the same temperature

Question 73

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

Answer 73

black pot

Question 74

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

Answer 74

cold room

Question 75

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

Answer 75

supports this common knowledge

Question 76

The planet Earth loses heat primarily by

Answer 76

radiation

Question 77

A good absorber of radiation is a

Answer 77

good emitter of radiation

Question 78

Aluminum has a specific heat capacity more than twice that of copper. Place equal masses of aluminum and copper wire in a flame and the one to undergo the fastest increase in temperature will be

Answer 78

copper

Question 79

Which unit represents the most energy?

Answer 79

Calorie

Question 80

The moderate temperatures of islands throughout the world has much to do with water's

Answer 80

high specific heat capacity

Question 81

Terrestrial radiation is

Answer 81

emitted by Earth

Question 82

Which temperature scale has the smallest sized degrees?

Answer 82

Fahrenheit

Question 83

A temperature difference of 10 Celsius degrees is also equal to a temperature difference of 10 on the

Answer 83

kelvin scale

Question 84

Room temperature on the Kelvin scale is about

Answer 84

300 k

Question 85

Heat energy is measured in units of

Answer 85

- calorie | - joules

Question 86

The specific heat capacity is highest for substances that absorb or release large quantities of heat for correspondingly

Answer 86

small temperature changes

Question 87

A substance that heats up relatively quickly has a

Answer 87

low specific heat capacity

Question 88

The fact that desert sand is very hot in the day and very cold at night is evidence that the specific heat capacity of sand is relatively

Answer 88

low

Question 89

One of water's interesting thermal properties is that when heated it takes a relatively

Answer 89

long time in changing temperature

Question 90

If the specific heat capacity of water were lower than it is, a nice hot bath would be a

Answer 90

shorter experience

Question 91

When we enlarge a photograph of an iron ring, the image of the hole becomes

Answer 91

larger

Question 92

When a bimetallic bar made of copper and iron strips is heated, the bar bends toward the iron strip. The reason for this is

Answer 92

copper expands more than iron

Question 93

Because of trapped air inside, snow is a

Answer 93

both a good insulator and a poor conductor

Question 94

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

Answer 94

cool

Question 95

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

Answer 95

- a difference in temperatures. | - the breath from puckered lips is cooler

Question 96

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

Answer 96

receding

Question 97

A region of expanding air tends to

Answer 97

cool

Question 98

A parcel of warmed air rises due to

Answer 98

buoyancy

Question 99

Objects that radiate relatively well

Answer 99

absorb radiation relatively well

Question 100

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

Answer 100

heat upwelling from the ground below is absent on a bridge

Question 101

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

Answer 101

less than its surroundings.

Question 102

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

Answer 102

- its reflectivity. - Earth's climate. - its average temperature. - its transparency