Terms in this set (89)
Three ways heat can be transferred:
Radiation, Convection, Conduction
Energy from the sun reaches the form of
Infrared Radiant Energy
The measure of how much the molecules in a substance are vibrating (motion in an object). The amount of thermal energy in an object
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
Poor conductor of thermal energy (or electricity. It resists the flow of heat energy.
A better conductor of heat will have a
Much more efficient heat transfer
The greater the molecular shaking,
the higher the tempurature
Three scales of measurement for tempurature
Fahrenheit, Centigrade, Kelvin
Water freezes at 32 degrees; boils at 212 degrees
Water Freezes at 0 degrees; boils at 100 degrees
Based on the molecular movement of a substance, and not on water's properties.
Absolute Zero. There is no molecular movement (-273 degrees Celsius)
Heat (thermal energy) is always transferred from an object with more molecular kinetic energy (hotter) to an object with
Less molecular kinetic energy (colder)
The movement of Electromagnetic Energy / Radiant Energy. The transfer of energy in electromagnetic waves that can move through a vacuum.
Can radiation travel through a vacuum?
All objects absorb and emit radiation (energy). (T/F)
Absorption of energy in an object is higher than the emission of energy
Absorption of energy is less than the emission of energy
The motion of the molecules in a substance.
The transfer of thermal energy between two objects or systems
Thermal energy is the total kinetic and potential energy of a system due to the motion of its atoms and molecules
The sun is very ____ with its output of heat and radiation
The amount of heat radiated from an object ____ as the temperature of an object _____.
Increases (for both)
The transfer of heat energy through the direct contact of two materials, because of the collisions of adjacent atoms or molecules
Conduction occurs at _____ rates in different materials
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.
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.
Convection Cell are at work in
Tectonic Plates, Oceans, the Atmosphere, and many others.
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)
Includes all forms of electromagnetic radiation; the types of radiation differ in their frequencies and wavelengths
Is air a good conductor of heat
Temperature and heat are ___ the same thing
Heat energy that is transferred by electromagnetic waves and does not need matter in which to travel
When two objects reach a temperature somewhere between the original temperatures (heat source and heat sink)
Accounts for how much additional heat you will lose because of convection. Usually a lower temperature than outside
The sun is the ultimate source of ____ for our planet
Heat is radiated in the form of
Velocity of Propagation of a Wave
Different waves in the electromagnetic spectrum have different
Heat is a form of
Energy (cannot be touched)
Frequency of Radio Waves
Frequency of Gamma Rays
How does a microwave oven work?
By agitating the water molecules present in most objects to create heat or infrared radiant energy
How is heat transferred during radiation?
A material that transmits energy; it is capable of gaining and losing thermal energy
The ______ of a conductor determine how easily heat energy moves back and forth in an object
The ____ determines how much ___ an object has
Motion; thermal energy
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
Why is air a poor conductor of heat
Because the molecules in gases are much farther apart than the molecules in solids
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
Insulation helps homes do what?
To protect your home from losing heat energy to the outside environment
A substance in which its molecules can flow freely past each other; it does not have a fixed shape
Convection can help create ___, which supply water to the earth.
Clouds. It also carries the moisture up high, helping the water cycle
A circular pattern of air rising and sinking.
Convection helps with the exchange of ____ necessary for life
What is thermal energy transferred by?
A difference in temperature between two objects
During conduction, the object that has a higher temperature
During conduction, the object that has a lower temperature
The study of thermal energy
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)
Energy is never lost (T/F)
What is the only process that transfers thermal energy in a solid substance?
Thermal resistance is represented by
Do all solids conduct thermal energy?
Yes, but some better than others
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
Coal (Is/Isn't) a good conductor of heat
When particles of matter come in contact with one another,
Energy is transferred
Animals use ____ to keep themselves warmer and trap in body heat
Convection (Can/Cannot) occur in space
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
All forms of matter are composed of atoms in constant ____.
All atoms have ____ energy.
What part of the air is heated by the sun's electromagnetic waves that is radiates?
The air at earth's surface
Which method of heat transfer is the least significant method of heating the Earth's atmosphere?
What kind of material can transfer heat by conduction?
Solids, liquids, and gases.
Heat gained by conduction or radiation is moved about the planet by what?
Objects that are good absorbers of radiation are good ____ as well.
The method used to transfer heat is usually the one that is what?
The most efficient
What state of matter is the best for the conduction of heat?
How is heat transferred in Convection?
Through the circulation of the air
Electromagnetic waves travel how fast?
The speed of light
Objects emit radiation when
High energy electrons in a higher atomic level fall down to lower energy levels
The energy lost in an object is emitted as
Electromagnetic radiation, or light
Heat Transfer is measured in units of what?
Which types of energy does a fire give off?
Infrared; Visible light
June puts her hands over the fire to warm them. What type of heat transfer makes this possible?
How do all types of Energy move through space?
It is radiated.
List all the types of electromagnetic energy according to their wave frequencies, small to large.
Radio, Micro, Infrared, Visible, Ultraviolet, X-Ray, Gamma Ray