Chapter 22

What is the difference between a conductor and an insulator?

A conductor conducts heat, while an insulator does not.

What is an insulator?

A material that is a poor conductor of heat and that delays the transfer of heat.

A poorly designed transmitting antenna will also be a poor or good receiver?

A poor receiver.

On a sunny day Earth's surface is a net what?

Absorber.

You can stick your hand into a hot pizza oven for several seconds without harm, Whereas you'd never touch the metal inside surfaces for even a second. Why?

Air is a poor conductor, so the rate of heat flow is from the hot air to your relatively cool hand is low. But touching the metal parts is a different story. Metal conducts heat very well, and a lot of heat in a short time is conducted into your hand when thermal contact is made.

What is radiant energy?

Any energy, including heat, that is transmitted by radiation

How does heat transfer by convection take place?

By the movement of heated material itself.

Record-breaking cold night occur when the skies are________?

Clear.

If you hold one end of a metal bar against a piece of ice, the end in your hand will son become cold . Does cold flow from the ice to your hand?

Cold does not flow from the ice to your hand. Heat flows from your hand to the ice. The metal is cold to your touch because you are transferring heat to the metal.

Neither ________ nor ________ is possible in the empty space between our atmosphere and the sun.

Convection , Conduction.

What produces wind?

Convection currents stirring in the atmosphere.

What is infrared waves?

Electromagnetic waves of frequencies lower than the red visible light.

Radiant energy is in the form of what kind of waves?

Electromagnetic waves.

A dark object that absorbs a lot must _____ a lot as well.

Emit.

At night Earth's surface is a net what?

Emitter.

Good absorbers are also good what?

Emitters.

Poor absorbers are poor what?

Emitters.

What is conduction in heat?

Energy is transferred from particle to particle within certain materials, or from one material to another which electrical charge can flow.

What is radiation?

Energy transmitted by electromagnetic waves.

Wood is a better insulator than glass. Yet fiberglass is commonly used to insulate wooden buildings. Why?

Fiberglass is a good insulator, many times better than glass, because of the air that is trapped among its fibers.

The friction of Earth presently beneath ice and snow is less or greater than the total area used for farmlands?

Greater.

You can hold your fingers beside the candle flame withough harm, but not above the flame. Why?

Heat travels upward by air convection. Since air is a poor conductor, very little heat travels sideways.

Shorter-wavelength infrared waves absorbed by our skin produce the sensation of what?

Heat.

The sun, a fireplace, and a lamp filament are all common sources of what?

Heat.

What does air do as it expands?

It cools.

What happens to fluid when it is heated?

It expands, becomes less dense, and rises.

What happens when air is compressed?

It heats up.

What happens to ice when it is put under pressure

It melts.

Is a air a poor or strong conductor?

It's a poor conductor.

Why does rising war air expand?

Less atmospheric pressure squeezes on it at higher altitudes.

When a molecule collides with a target molecule that is receding, its rebound speed after the collision is less or higher than it was before the collision?

Less.

Objects at low temperatures emit long or short waves?

Long.

What is a conductor?

Material through which heat can be transferred.

What is the best conductor?

Metal.

Earth's average temperature can be changed by ______ and also by ________.

Natural causes and human activity.

Are poor absorbers good emitters?

No.

Can an insulator totally prevent heat from getting through it?

No.

A slightly higher Earth temperature means slightly warmer ________?

Oceans.

Earth's temperature depends on the energy balance between incoming solar radiation and ________?

Outgoing terrestrial radiation.

Good reflectors are poor or strong absorbers?

Poor absorbers.

Energy consumption is related to what?

Population Size.

Energy consumption is related to what?/

Population size.

The rate of cooling of an object whether by conduction, convection, or radiation is approximately what?

Proportional to the temperature difference.

What is terrestrial radiation?

Radiant energy emitted from Earth.

A perfect absorber reflects no what and appears perfectly black?

Radiant energy.

An energy, including heat, that is transmitted by radiation is called what?

Radiant energy.

Anything with a mirror-like surface reflects most of the _________ it encounters?

Radiant energy.

Every surface, hot or cold, both absorbs and emits what?

Radiant energy.

The sun's heat is transmitted by what?

Radiation.

List these types of radiant energy from order of wavelength, from longest to shortest (light waves, radio waves, and infrared waves).

Radio waves, infrared waves, and light waves.

High-temperature objects radiate short or long waves?

Short waves.

Objects at high temperatures emit long or short waves?

Short.

If materials are in the same vicinity, they should have the same what?

Temperature and room temperature.

The wavelength of radiation depends on what?

Temperature.

Then density of water depends on its what?

Temperature.

What is radioactive?

Term applied to an atom with a nucleus that is unstable and that can spontaneously emit a particle and become the nucleus of another element.

Which will normally cool faster, a black pot of hot tea or a silvered pot of hot tea?

The black pot will cool faster.

What is wavelength?

The distance from the top of the crest of a wave to the top of the following crest, or equivalently, the distance between successive identical parts of the wave.

What is conduction in electricity?

The flow of charge through a conductor.

Why does a piece of room- temperature metal feel cooler to the touch than paper, wood. or cloth?

The metal feels colder because it is a better conductor.

Is it more efficient to paint a heating radiator black or silver?

The radiators should be painted a dull black.

What is Newton's law of cooling?

The rate of cooling on an object-weather by conduction, convection, or radiation-is approximately proportional to the temperature difference between the object and its surroundings.

What is Archimedes' principle?

The relationship between buoyancy and displaced fluid.

When H2O in the vapor phase condenses, is the surrounding air warmed or cooled?

The surrounding air is warmed.

What is the greenhouse effect?

The warming effect whose cause is that short-wavelength radiant energy from the sun can enter the atmosphere and be absorbed by Earth more easily than long-wavelength energy from Earth can leave.

What is the role of "loose" electrons in heat conductors?

They make it easier to conduct heat, and electricity, through materials.

What do convection currents stirring the atmosphere produce?

They produce winds.

True or False. Earth's temperature depends on the energy balance between incoming solar radiation and outgoing solar radiation.

True.

What causes convection currents?

Uneven absorption causes uneven heating of the air near the surface.

What are convection currents produced by?

Uneven heating.

Does heat travel upward or downward by air convection?

Upward.

When does a liquid absorb energy?

When it evaporates.

When does a gas emit energy?

When it liquifies.

When does a solid absorb energy?

When it melts.

When does a liquid emit energy?

When it solidifies.

What is convection?

Where heating occurs by currents in a fluid.

Are good absorbers also good emitters?

Yes.

Does convection occur in all fluids?

Yes.

Convection occurs in what?

in all fluids, whether liquid or gas.

Wood, wool, straw, paper, cork,and polystyrene are examples of what?

insulators