Heat Transfer

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All atoms have ____ energy.

Thermal (heat)

Thermal Energy

Thermal energy is the total kinetic and potential energy of a system due to the motion of its atoms and molecules

When rapidly moving molecules collide with molecules in another object

They will transfer some of their energy, in the form of heat, to the molecules

How is heat transferred in Convection?

Through the circulation of the air

Insulation helps homes do what?

To protect your home from losing heat energy to the outside environment

All objects absorb and emit radiation (energy). (T/F)

True

Energy is never lost (T/F)

True

Light

Visable energy

Thermal resistance is represented by

r

Three ways heat can be transferred:

Radiation, Convection, Conduction

Objects that are good absorbers of radiation are good ____ as well.

Radiators

List all the types of electromagnetic energy according to their wave frequencies, small to large.

Radio, Micro, Infrared, Visible, Ultraviolet, X-Ray, Gamma Ray

The greater the molecular shaking,

the higher the tempurature

Tempurature

The measure of how much the molecules in a substance are vibrating (motion in an object). The amount of thermal energy in an object

The method used to transfer heat is usually the one that is what?

The most efficient

Heat

The motion of the molecules in a substance. The transfer of thermal energy between two objects or systems

Radiation

The movement of Electromagnetic Energy / Radiant Energy. The transfer of energy in electromagnetic waves that can move through a vacuum.

Electromagnetic waves travel how fast?

The speed of light

Thermodynamics

The study of thermal energy

Conduction

The transfer of heat energy through the direct contact of two materials, because of the collisions of adjacent atoms or molecules

Convection

The transfer of heat energy through the movement of the molecules of a fluid, due a circular cycle in which heat rises and transfers the energy.

0 Kelvin

Absolute Zero. There is no molecular movement (-273 degrees Celsius)

Wind Chill

Accounts for how much additional heat you will lose because of convection. Usually a lower temperature than outside

Describe the cycle of convection

As a fluid is heated, its molecules expand, becoming lighter, and it rises. It is then replaced by the cold fluid, which is more dense, and sinks to the bottom. As the hot fluid rises, it will eventually lose its heat (due to it transferring it to something else or by other means) and fall aswell. Meanwhile, the cold fluid will become heated and rise like the first time. It is a continuous circular cycle.

The ______ of a conductor determine how easily heat energy moves back and forth in an object

Atomic Properties

Kelvin

Based on the molecular movement of a substance, and not on water's properties.

Why is air a poor conductor of heat

Because the molecules in gases are much farther apart than the molecules in solids

How does a microwave oven work?

By agitating the water molecules present in most objects to create heat or infrared radiant energy

Convection (Can/Cannot) occur in space

Cannot

Convection can help create ___, which supply water to the earth.

Clouds. It also carries the moisture up high, helping the water cycle

What is the only process that transfers thermal energy in a solid substance?

Conduction

Which method of heat transfer is the least significant method of heating the Earth's atmosphere?

Conduction

The sun is very ____ with its output of heat and radiation

Constant

Heat gained by conduction or radiation is moved about the planet by what?

Convection

June puts her hands over the fire to warm them. What type of heat transfer makes this possible?

Convection

How do good insulators cut down on the amount of energy used to heat a home?

Good insulators allow less heat to escape from inside to the air outside, so you do not have to expend as much energy replenishing the lost heat

Infrared Radiant Energy

Heat

Radiant Energy

Heat energy that is transferred by electromagnetic waves and does not need matter in which to travel

Frequency of Gamma Rays

High

Objects emit radiation when

High energy electrons in a higher atomic level fall down to lower energy levels

Absorption of energy in an object is higher than the emission of energy

Hotter

Energy from the sun reaches the form of

Radiation

Velocity of Propagation of a Wave

300,000 km/s

Convection Cell

A circular pattern of air rising and sinking.

What is thermal energy transferred by?

A difference in temperature between two objects

Conductor

A material that transmits energy; it is capable of gaining and losing thermal energy

Fluid

A substance in which its molecules can flow freely past each other; it does not have a fixed shape

Absorption of energy is less than the emission of energy

Cooler

Conduction occurs at _____ rates in different materials

Different

Heat Source

During conduction, the object that has a higher temperature

Heat Sink

During conduction, the object that has a lower temperature

Heat is radiated in the form of

Electromagnetic Waves

The energy lost in an object is emitted as

Electromagnetic radiation, or light

How is heat transferred during radiation?

Electromagnetically

The sun is the ultimate source of ____ for our planet

Energy

Heat is a form of

Energy (cannot be touched)

When particles of matter come in contact with one another,

Energy is transferred

Three scales of measurement for tempurature

Fahrenheit, Centigrade, Kelvin

Nicolas Leonard Sadi Carnot

Founder of the field of Thermodynamics. Studied how steam is used to power engines, and his work helped with the construction of steam engines. (He was French)

Different waves in the electromagnetic spectrum have different

Frequencies

Electromagnetic Spectrum

Includes all forms of electromagnetic radiation; the types of radiation differ in their frequencies and wavelengths

The amount of heat radiated from an object ____ as the temperature of an object _____.

Increases (for both)

Which types of energy does a fire give off?

Infrared; Visible light

Animals use ____ to keep themselves warmer and trap in body heat

Insulators

Coal (Is/Isn't) a good conductor of heat

Isn't

How do all types of Energy move through space?

It is radiated.

When a fluid is heated,

Its molecules spread out, its molecules move more quickly, its molecules gain great volume, and its molecules collide with each other more frequently (transferring energy)

Heat (thermal energy) is always transferred from an object with more molecular kinetic energy (hotter) to an object with

Less molecular kinetic energy (colder)

Frequency of Radio Waves

Low

All forms of matter are composed of atoms in constant ____.

Motion

The ____ determines how much ___ an object has

Motion; thermal energy

A better conductor of heat will have a

Much more efficient heat transfer

Is air a good conductor of heat

No

Temperature and heat are ___ the same thing

Not

Convection helps with the exchange of ____ necessary for life

Nutrients

Insulator

Poor conductor of thermal energy (or electricity. It resists the flow of heat energy.

What state of matter is the best for the conduction of heat?

Solid

What kind of material can transfer heat by conduction?

Solids, liquids, and gases.

Convection Cell are at work in

Tectonic Plates, Oceans, the Atmosphere, and many others.

Thermal Conductance (Conductivity)

The ability to conduct/allow to pass through thermal energy. Measured in the amount of thermal energy conducted in one hour. The rate at which an object transfers thermal energy

What part of the air is heated by the sun's electromagnetic waves that is radiates?

The air at earth's surface

Why are there more thunderstorms near the equator?

The air is the warmest there (because more sunlight reaches it), and there are many oceans, or other bodies of water

What will happen if a cold object comes into contact with a hotter one?

The hotter object will transfer its heat to the colder one until they are the same temperature

Centigrade

Water Freezes at 0 degrees; boils at 100 degrees

Fahrenheit

Water freezes at 32 degrees; boils at 212 degrees

Heat Transfer is measured in units of what?

Watts

Thermal Equillibrium

When two objects reach a temperature somewhere between the original temperatures (heat source and heat sink)

Can radiation travel through a vacuum?

Yes

Do all solids conduct thermal energy?

Yes, but some better than others


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