“EARTH’S ENERGY“

5.1) Electromagnetic Energy. is the ability to do work. Everything that is done in the universe involves the use or transfer of energy.

There are two sources for Earth’s heat energy. Internal source heat from earth’s interior. Comes from; 1 - remnant heat 2 - radioactive decay.

2) External source Comes from; Insolation – energy from the sun. (In/sol/ation) incoming solar radiation. This drives most Earth surface processes.

Electromagnetic Energy. energy that is radiated (given off) by all matter that is not at absolute zero. absolute zero = the lowest possible temperature. 0 Kelvin or -273oC.(-459.67F) the higher the temperature, the greater the amount of energy that is given off.

Characteristics and Types of Electromagnetic Energy. different types of electromagnetic energy are distinguished by their wavelength. wavelength - the distance from one crest of a wave to the next crest.

diagram; | | | | crest crest trough trough one wavelength

Electromagnetic Spectrum See ESRT p. 14 Long Wave Energy Low energy Short Wave Energy High energy

The electromagnetic spectrum a model that shows all the types of electromagnetic energy. Visible light is the only portion of the spectrum that we can see with our eyes.

1) Which type of electromagnetic radiation has the longest wavelength? (1) ultraviolet (3) visible light (2) gamma rays (4) radio waves

2) Which graph best represents the relative wavelengths of the different forms of electromagnetic energy?

3) Which color of the visible spectrum has the shortest wavelength? (1) violet (3) yellow (2) blue (4) red

4) In which list are the forms of electromagnetic energy arranged in order from longest to shortest wavelengths? (1) gamma rays, x rays, ultraviolet rays, visible light (2) radio waves, infrared rays, visible light, ultraviolet rays (3) x rays, infrared rays, blue light, gamma rays (4) infrared rays, radio waves, blue light, red light

5) What is the basic difference between ultraviolet, visible, and infrared radiation? (1) half-life (3) wavelength (2) temperature (4) wave velocity

Main Ideas and Supporting Details DATE Main Ideas and Supporting Details

There are three types of spectrum. continuous a continuous band of colors, with one color blending into the next, the “real” rainbow. Produced by a glowing solid or liquid, or by a highly compressed glowing gas.

2) bright line (emission) dark background with a series of thin brightly colored lines. Produced from a non-compressed gas.

3) dark line (absorption) a continuous spectrum with thin black lines. Produced from the sun’s light, where light passes through a cooler gas.

Interactions between Electromagnetic Energy and an Environment. When electromagnetic waves strike an object they may be….

1) refracted bent.

2) reflected bounced off.

3) scattered refracted and/or reflected in various directions.

4) transmitted passed through the material.

5) absorbed taken into the material.

Surface Properties and Absorption. The characteristics of the surface of a material will determine the amount of electromagnetic energy that can be absorbed.

Characteristics 1) Color dark color – absorbs well. light color – absorbs poorly. (it reflects energy) 2) Texture rough surface – absorbs well. smooth surface – absorbs poorly. (it reflects energy)

A material that absorbs electromagnetic energy well will A material that absorbs electromagnetic energy well will.. heat up quickly.

A material that heats up quickly will also A material that heats up quickly will also.. radiate (gives off) energy well. It will cool quickly

5-2) Transfer of Energy Energy moves from a … region of high concentration (a source) to a … region of low concentration (a sink). SOURCE SINK (high) (low)

heat energy – energy that is transferred from a region of high temperature to a region of lower temperature.

Achieving Dynamic Equilibrium Heat will move from a .. source to a sink until their energies are equal. Dynamic Equilibrium is achieved when.. the amount of energy being gained is equal to the amount of energy being lost.

3 Methods of Energy Transfer

1 - CONDUCTION Heat energy is transferred from atom to atom, when vibrating atoms collide. Conduction is most effective in solids. diagram:

HOT

Main Ideas and Supporting Details DATE Main Ideas and Supporting Details

2 - CONVECTION caused by differences in density. warmer portions have a lower density and rise. cooler portions have a greater density and sink. only occurs in fluids; liquids and gases. convection currents occur in; atmosphere, the hydrosphere, & below the lithosphere. Diagram:

3 - RADIATION. caused by electromagnetic waves. no medium is needed to transfer electromagnetic waves. examples; sunlight warming the earth or heating the inside of a car. diagram;

Diagram 1; Earth

Energy travels through space

The inside is hotter than the temperature outside. Diagram 2; Inside car

5-3) Transformation of Energy changing one type of energy into another.

Examples; friction – kinetic energy is transformed into heat energy. glacier flowing down a valley. waves Wind blowing on the ocean. energy from atmosphere to hydrosphere.

Transformations of Mechanical Energy potential + kinetic energy. the energy of an object that is not related to the motion of atoms.

kinetic energy - energy of motion. the faster an object moves, the greater its kinetic energy.

potential energy - energy of position, or phase. (“stored energy”) the higher an object is above the center of the earth, the greater its potential energy.

Example; Waterfall

Water at the top of a waterfall has potential energy. as the water falls, some of its potential energy becomes kinetic energy. diagram

(Build your own waterfall) Hydroelectric Capture this energy… (Build your own waterfall) Hydroelectric Height 726 River view of the eventual site of Hoover Dam, circa 1904

Transformation of Electromagnetic Energy Electromagnetic energy absorbed by an object is reradiated at a longer wavelength. high temp. emits short wavelength. lower temp emits longer wavelength.

Earth example; Short wavelength radiation from the sun (insolation) is absorbed and … ….reradiated as longer wavelength radiation (infrared) from the earth. diagram

Long wave from Earth Short wave from sun.

Temperature

temperature is a measure of the average kinetic energy of the particles of a body of matter. One molecule Atoms in a gas

The instrument that is used to measure temperature is a …. thermometer Galileo thermometer digital Mercury thermometer IR thermometer

There are three different temperature scales… Fahrenheit Celsius Kelvin – do not use degree sign; absolute zero is 0K use ESRT to do conversions

200 oF = o C = K oF = 60oC = K oF = oC = 280 K 5 oF = oC = K oF = -25 oC = K 93 367 140 333 46 8 -15 258 248 -13

Heat and Thermal Energy FYI Heat – is the transfer or flow of energy from a Hot object to one that is cooler. Thermal energy – When you feel a warm object You are actually feeling thermal energy – the movement of molecules that make up the object.

Heat energy is measured in a unit called a joule. 4.184 joules = 1 calorie 1 calorie heat needed to raise one gram of liquid water by one degree Celsius.

Different materials heat up at different rates. Specific Heat heat needed to raise one gram of any substance one degree Celsius. or…specific heat can be defined as the resistance a material presents to heating up or cooling off.

What do you need to know?

see Earth Science Reference Tables. Liquid water has the highest specific heat of all naturally occurring substances. see Earth Science Reference Tables. For a 1 gram sample.. 4.18 J raises temp 1oC 4.18 J raises temp 32oC

Heat Energy and Changes of State

Changes in State Melting Solid to liquid. (ice cubes melting) melting titanium

Solidification (freezing) Changes in State Solidification (freezing) Liquid to solid (water freezing) Toronto

Evaporation (vaporization) Changes in State Evaporation (vaporization) Liquid to gas (boiling water)

Changes in State Condensation Gas to liquid (rain, mirror in bathroom) dew

Changes in State Sublimation Solid to gas (decrease in snowpack) dry ice

Changes of State (phase) solid liquid gas

Changes of State (phase) HEAT IS RELEASED precipitation solidification condensation solid 334 J/g liquid 2260 J/g gas vaporization melting sublimation HEAT IS ABSORBED

Stored Heat and Changes of States During a change of state, heat added does not change the temperature. The added heat energy is being converted to a kind of potential energy, or stored heat.

Draw and label diagram; Heating of Water gas evaporation 100oC condensation temperature liquid melting 0oC freezing solid -100oC time

Earth's Energy Supply

1 - Solar Energy Of all the types of electromagnetic radiation from the sun, the one with the greatest intensity is … visible light. Solar energy is produced by … nuclear fusion.

2 - Earth's own Energy 1 - heat that remains from when the Earth formed. 2 - nuclear decay of radioactive materials.