Physics chapter 7

Metals are both good heat and electrical conductors due to

A good heat conductor

A poor conductor of heat is

Your toes feel warmer on a rug than on a tile floor because the rug

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

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

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

The process of convection occurs in

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

Hot steam that issues from a pressure cooker expands and

Convection currents in the air near a seashore are produced by

Coastal winds shift from night to day due to

Blow on your hand with your open mouth and you feel the warmth of your breath. Pucker your lips so your breath expands as you blow and your breath is

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

When a volume of air is compressed, its temperature

The gush of steam that issues from the escape valve of a pressure cooker is relatively cool

Radiant energy emitted by our planet is

The higher the frequency of a wave, the

The average frequency of radiant energy is directly proportional to the

The higher the temperature of an object, the

The higher the temperature of an object, the

A star that is twice as hot as another has twice the

If an object radiates more energy than it absorbs, its

If an object radiates more energy than it reflects, its

Objects that are good radiators generally

Hot water will cool to room temperature faster in a

Cold water will warm to room temperature faster in a

To minimize heat loss it is best that a teapot be

The pupil of your eye is a net

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

If air were a better conductor than it is, nighttimes on Earth would be

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

A good absorber of radiation is a

A good reflector of radiation is a

The Sun’s radiant energy is composed of shorter wavelengths than the Earth’s because the Sun

The silver coating on the glass surfaces of a Thermos bottle reduces energy that is transferred by

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

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

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

Newton’s law of cooling applies to objects that are

A friend says that a can of beverage will cool faster in the coldest part of a refrigerator. Knowledge of Newton’s law of cooling

A can of soft drink will cool faster if placed in what part of a refrigerator?

A red-hot piece of iron will cool faster in a

Compared to a glass of ice water with ice, a glass of plain ice-cold water without ice on a warm day will warm up

If the greenhouse effect on Earth were absent, Earth’s average temperature would be about

To say you can never change only one thing means that when you change something,

Glass in a florist’s greenhouse blocks radiation of

Glass and the atmosphere are largely opaque to

Transparency of the atmosphere is lowest for radiation of

The interior of a greenhouse emits long-wavelength radiation due to its

Heating the Earth’s atmosphere is caused by energy

The Earth loses heat mainly by

Which is not a phase of matter

The molecules in a room-temperature glass of water jostle around at

Evaporation is a cooling process because

To say that evaporation is a cooling process is to say that the

Put a saucer of water on your table. A process that occurs in the saucer is

The dew that forms on a cold soda can when taken from a refrigerator is due to

Sublimation is a change of phase from solid to gas without

A mixture of light and heavy molecules make up a sample of gas. The temperature of the gas is constant, which means all the molecules have the same average

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

Both heavy and light molecules make up a sample of gas. On average, the faster molecules are the

In a gaseous mixture of hydrogen and oxygen, the higher-temperature molecules are

In a gaseous mixture of hydrogen and oxygen, the molecules having the greatest average kinetic energy are

In a gaseous mixture of hydrogen and oxygen, the faster molecules on average are

In a gaseous mixture of hydrogen and oxygen, the slower molecules on average are

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

A hot dog pants

Pigs wallow in mud mainly to

A soda pop can with a small amount of water is on a hot stove. Soon steam comes from its opening. When the can is quickly inverted into a pan of water, the can is crushed by

Consider a steaming aluminum soda-pop can that contains a small amount of boiling water. When it is quickly inverted into a bath of cooler water, the can is dramatically crushed. This is due to the rapidly reduced pressure inside the can by

The process of boiling water tends to

Boiling can be thought of as evaporation

Boiling and freezing can occur at the same time when water is subjected to

When heat is added to boiling water, the water temperature

Increased air pressure on the surface of hot water tends to

In the mountains, water boils at

When salt is introduced to water, the temperature at which freezing occurs is

Food is cooked faster in a pressure cooker because of the

If you want to cook eggs by boiling them while in the mountains, then compared with cooking at sea level you should

When bringing water to a boil in the mountains, the time needed to reach the boiling point is

Melting and freezing are both

Keep decreasing the shaking of atoms in a liquid and it will

When water changes to ice, water molecules

When ice changes phase to become water, energy is

An researcher discovers a harmless and tasteless salt, which, when added to water changes its boiling point. The market value for this salt will be best if the salt

Which requires more energy?

Which would burn the most?

Steam burns are much more damaging than boiling-water burns because steam

Steam burns are more damaging than burns caused by boiling water because steam

When steam condenses to water, energy is

When a gas is changed to a liquid phase, the gas

When a solid is changed to a liquid phase, the solid

When gases change to a liquid phase, they

We feel uncomfortably warm on a muggy day because water molecules are

We are warmed by condensation because water molecules in the air striking our bodies

When snow forms in clouds, the surrounding air is

When a gas changes phase to become a solid, energy is

Suppose you walk on red hot coals with bare feet. Providing bits of coal do not stick to your feet, it would be safer if your feet are

To melt 50 g of 0°C ice requires

The number of grams of ice that can be melted by 1 g of 100°C steam is

If the composition of the upper atmosphere were changed to permit a greater amount of terrestrial radiation to escape, what effect would this have on Earth’s climate?

Alcohol evaporates faster than water at the same temperature. Which cools your skin more: alcohol, or the same amount of water, evaporating from your skin?

From best to worst, rank these materials as heat conductors: (a) copper wire, (b) snow, and a (c) glass rod.

From greatest to least, rank the energy needed for these phase changes for equal amounts of H2O: (a) from ice to ice water, (b) from ice-water to boiling water, and (c) from boiling water to steam.

A block of ice at 0∘C is dropped from a height that causes it to completely melt upon impact. Assume that there is no air resistance and that all the energy goes into melting the ice.

What is the height necessary for this to occur. [ Hint: Equate the joules of gravitational potential energy to the product of the mass of ice and its heat of fusion (Lf = 335,000 J/kg).].

does answer depend on mass

A 11-kg iron ball is dropped onto a pavement from a height of 100 m . Suppose that half of the heat generated goes into warming the ball.

What is the temperature increase of the ball. (The specific heat capacity of iron is 450 J/kg ⋅ ∘C. Use 9.8 N/kg for g.).

is answer same for iron ball of any mass?

Quantity of heat: Q=cmΔT

Find what heat in calories (cal) is required to increase the temperature of 60 g water from 0∘C to 60 ∘C. The specific heat capacity of water is 1 cal/g⋅∘C.