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New Unit! Energy in Earth Processes Question of the Day What is electromagnetic energy, New Unit! Energy in Earth Processes Question of the Day What is electromagnetic energy, and how does it affect me? What causes rainbows? 77

Energy • Ability to do work • Earth processes driven by 2 sources: 1) Energy • Ability to do work • Earth processes driven by 2 sources: 1) Major (external): the sun 2) Minor (internal): Earth’s interior

Electromagnetic Energy • Given off by all matter above 0 K • Travels @ Electromagnetic Energy • Given off by all matter above 0 K • Travels @ speed of light: 3. 0 x 108 m/s • Transverse waves (right angles to direction)

• Types classified by wavelength (distance between crests) • Types classified by wavelength (distance between crests)

Frequency • Cycles per unit of time Q: Which wave has the highest frequency: Frequency • Cycles per unit of time Q: Which wave has the highest frequency: long or short? Q: Which has the highest energy?

Low Frequency = Low Energy High Frequency = High Energy Low Frequency = Low Energy High Frequency = High Energy

Electromagnetic Spectrum • Classifies energy by wavelength • Short Wave, Long Wave, Visible Light Electromagnetic Spectrum • Classifies energy by wavelength • Short Wave, Long Wave, Visible Light

1. Short Waves • Gamma rays, X rays, Ultraviolet (UV) • Most dangerous • 1. Short Waves • Gamma rays, X rays, Ultraviolet (UV) • Most dangerous • Invisible • High frequency, high energy Sources: answers. com, schools. medphys. ucl. ac. uk, floridadisaster. org

2. Long Waves • Infrared, Microwaves, Radio Waves • Least dangerous • Invisible • 2. Long Waves • Infrared, Microwaves, Radio Waves • Least dangerous • Invisible • Low frequency, low energy Sources: target. com, sci-toys. com, abledata. com

3. Visible Light 3. Visible Light

Long Wave = Low Energy = Low Frequency Short Wave = High Energy = Long Wave = Low Energy = Low Frequency Short Wave = High Energy = High Frequency

ESRT Activity 1. Mark Short Wave, Long Wave @ each end 2. Mark High ESRT Activity 1. Mark Short Wave, Long Wave @ each end 2. Mark High Frequency, Low Frequency 3. Mark High Energy, Low Energy 4. Draw increasing wavelengths @ bottom

1. Which has a shorter wavelength than red light: Radio waves, microwaves, infrared, UV? 1. Which has a shorter wavelength than red light: Radio waves, microwaves, infrared, UV? 2. Which color of the visible spectrum has the shortest wavelength? 3. Which has the lowest frequency: radio waves, infrared rays, red light, gamma rays? 4. Compared to the speed of gamma rays, infrared is: faster, slower, the same 5. Electromagnetic spectrum classifies by: temperature, speed, source, wavelength?

1. Which has a shorter wavelength than red light: Radio waves, microwaves, infrared, UV? 1. Which has a shorter wavelength than red light: Radio waves, microwaves, infrared, UV?

2. Which color of the visible spectrum has the shortest wavelength? 2. Which color of the visible spectrum has the shortest wavelength?

3. Which has the lowest frequency: radio waves, infrared rays, red light, gamma rays? 3. Which has the lowest frequency: radio waves, infrared rays, red light, gamma rays?

4. Compared to the speed of gamma rays, infrared is: faster, slower, same 4. Compared to the speed of gamma rays, infrared is: faster, slower, same

5. The electromagnetic spectrum classifies energy by: temperature, speed, source, or wavelength? 5. The electromagnetic spectrum classifies energy by: temperature, speed, source, or wavelength?

Question of the Day How does energy interact with surfaces? In the summer, which Question of the Day How does energy interact with surfaces? In the summer, which is hotter when you touch it: a black car or white car? Why? 78

Energy Interactions • Refraction • Reflection • Scattering • Absorption Alaska-in-pictures. com Energy Interactions • Refraction • Reflection • Scattering • Absorption Alaska-in-pictures. com

Energy Interactions Affect Weather Energy Interactions Affect Weather

Reflection • Waves bounce off material Alaska-in-pictures. com Reflection • Waves bounce off material Alaska-in-pictures. com

Refraction • Waves bend through materials of varying density • Direction of waves changes Refraction • Waves bend through materials of varying density • Direction of waves changes

Scattering • Waves refracted and/or reflected in various directions Scattering • Waves refracted and/or reflected in various directions

Absorption • Waves taken in by the material Absorption • Waves taken in by the material

Which is scatter, reflection, refraction, absorption? A Refraction B C Reflection Scatter D Absorption Which is scatter, reflection, refraction, absorption? A Refraction B C Reflection Scatter D Absorption

Characteristics That Affect Absorption Color • Dark colors absorb better than light • Dark Characteristics That Affect Absorption Color • Dark colors absorb better than light • Dark colors heat up and cool off faster • Fast absorption = Fast radiation (give off energy)

Texture • Rough vs. smooth • Rough absorbs more, reflects less Would a mirror Texture • Rough vs. smooth • Rough absorbs more, reflects less Would a mirror absorb more or less than a rock?

1. Which is the best absorber of energy: red, white, black, or pink? 2. 1. Which is the best absorber of energy: red, white, black, or pink? 2. Painting a house a lighter color will reduce the solar energy: absorbed, scattered, reflected, or refracted? 3. Compared with a dull, rough rock, a shiny smooth rock will cause sunlight to be: reflected, refracted, scattered, or absorbed?

Which is Hotter? 1) 220º F or 220 K? 2) 100º C or 100º Which is Hotter? 1) 220º F or 220 K? 2) 100º C or 100º F? 3) 100º C or 100 K? 4) 32º C or 0º F? 5) 32º F or 0º C?

Question of the Day How does energy move? If you’re warm and hold hands Question of the Day How does energy move? If you’re warm and hold hands with someone cold, what happens? 79

How Does Energy Move? Put your hand on the table. How’s it feel? • How Does Energy Move? Put your hand on the table. How’s it feel? • Your hand is “Hot” • The table is “Cool” • Which way is the heat moving? High Energy Low Energy ENERGY FLOWS FROM HIGH TO LOW!

Source – Where heat /energy comes from. Heat - Low Concentration Sink – Where Source – Where heat /energy comes from. Heat - Low Concentration Sink – Where heat/energy goes towards. Energy flows from Source to Sink! SINK Heat - High Concentration SOURCE

Dynamic Equilibrium (Radiative Balance) • Heat moves from source to sink until energies are Dynamic Equilibrium (Radiative Balance) • Heat moves from source to sink until energies are equal • Temperature remains constant

Question of the Day What are the 3 methods that energy moves by? 1. Question of the Day What are the 3 methods that energy moves by? 1. Does increasing temperature decrease or increase density? 2. Does decreasing temperature decrease or increase density? 80

Energy Scene #1 Identify: 1. Where is the heat Source? 2. Where is the Energy Scene #1 Identify: 1. Where is the heat Source? 2. Where is the heat Sink? 3. Which direction is energy flowing? • Energy transferred through liquids & gases by differences in density: Convection

Convection Ex. : 1. Atmosphere 2. Earth’s mantle (between crust & core) Convection Ex. : 1. Atmosphere 2. Earth’s mantle (between crust & core)

Convection Cell (or Current) ● Circular movement Least Dense Starts to Cool Heats Up Convection Cell (or Current) ● Circular movement Least Dense Starts to Cool Heats Up Most Dense Cools Down

Convection Cell (or Current) Convection Cell (or Current)

Warm Up Cool Down Warm Up Cool Down

Identify: Energy Scene #2 1. Where is the heat Source? 2. Where is the Identify: Energy Scene #2 1. Where is the heat Source? 2. Where is the heat Sink? 3. Which direction is energy flowing? • Energy is transferred from particle to particle: Conduction

Conduction • Most effective in solids, especially metals, since particles are close together Ex. Conduction • Most effective in solids, especially metals, since particles are close together Ex. : 1. Getting burnt by touching stove. 2. Melting ice in hand. 3. Fire poker getting hot.

Energy Scene #3 Identify: 1. Where’s the heat Source? 2. Where’s the heat Sink? Energy Scene #3 Identify: 1. Where’s the heat Source? 2. Where’s the heat Sink? 3. Which direction is energy flowing? • Energy transferred through space or gases: Radiation

Radiation • Higher an object’s temperature, more energy it radiates Ex. : 1. The Radiation • Higher an object’s temperature, more energy it radiates Ex. : 1. The Sun 2. Light bulb 3. Radiator • Good radiators = good absorbers

Summary Transfer of Energy Convection → Movement Due to Different Densities Conduction → Contact Summary Transfer of Energy Convection → Movement Due to Different Densities Conduction → Contact Radiation → Waves

Match Them Up! Energy is transferred … ? A. Through liquids & gases by Match Them Up! Energy is transferred … ? A. Through liquids & gases by differences in 2. Conduction density 1. Radiation 3. Convection B. From particle to particle C. Through space or gases

Question of the Day How is energy transformed? Which is… 1) Radiation 2) Conduction Question of the Day How is energy transformed? Which is… 1) Radiation 2) Conduction 3) Convection 82

Transfer of Energy Convection → Movement Conduction → Contact Radiation → Waves Transfer of Energy Convection → Movement Conduction → Contact Radiation → Waves

Kinetic vs. Potential Energy Kinetic Energy: object in motion • Faster something moves, greater Kinetic vs. Potential Energy Kinetic Energy: object in motion • Faster something moves, greater its kinetic energy • More mass = greater kinetic energy

Potential Energy: “stored energy” • Related to position or phase • Ex. : higher Potential Energy: “stored energy” • Related to position or phase • Ex. : higher object is above Earth, greater its potential to fall = greater potential energy. • More mass = more potential energy

Transformation • Potential energy can be transformed into kinetic • Ex. : Waterfall Water Transformation • Potential energy can be transformed into kinetic • Ex. : Waterfall Water at top - high potential Water falling - some potential energy → some kinetic energy, resulting in an increase in speed.

Heat Production Friction • Glaciers – Kinetic energy transformed into heat energy at interface Heat Production Friction • Glaciers – Kinetic energy transformed into heat energy at interface (boundary) between glacier and valley walls.

Transformation of Electromagnetic Energy • Incoming solar radiation (insolation) – Short wave • Energy Transformation of Electromagnetic Energy • Incoming solar radiation (insolation) – Short wave • Energy re-radiated by Earth – Long wave

What kind of energy is insolation? What kind is re-radiated by Earth? What kind of energy is insolation? What kind is re-radiated by Earth?

Temperature: measure of average kinetic energy of particles in matter. • Greater kinetic energy, Temperature: measure of average kinetic energy of particles in matter. • Greater kinetic energy, higher temperature.

Heat Energy Heat energy (thermal energy): energy of motion of particles of matter. • Heat Energy Heat energy (thermal energy): energy of motion of particles of matter. • Heat is transferred b/c of difference in temperature • Measured in joules: metric unit of energy

Conservation of Energy • Energy can neither be created nor destroyed. • Energy can Conservation of Energy • Energy can neither be created nor destroyed. • Energy can only be transformed from one state to another. • Ex. : potential → kinetic.

1. An interface is: a) change in state of environment; b) region below Earth’s 1. An interface is: a) change in state of environment; b) region below Earth’s surface; c) region with no changes; d) boundary across which energy may be exchanged. 2. Friction at an interface always produces: a) transformation of energy; b) form of pollution; c) chemical change; d) phase change. 3. Electromagnetic energy that reaches Earth from sun is called: a) insolation; b) conduction; c) specific heat; d) terrestrial radiation.

Question of the Day What is Specific Heat? 1) Is the energy transfer above: Question of the Day What is Specific Heat? 1) Is the energy transfer above: Radiation, Convection, or Conduction? 2) Which is the source, which is the sink? 3) The thermometer is measuring average kinetic energy or potential energy? 84

What is Specific Heat? • Quantity of heat needed to raise temp. of 1 What is Specific Heat? • Quantity of heat needed to raise temp. of 1 gm. of any substance 1º C. • Resistance to heating up or cooling off. High Specific Heat Low Specific Heat Need More Energy Need Less Energy

• Takes 4. 18 joules to raise temp. of 1 gm. liquid water • Takes 4. 18 joules to raise temp. of 1 gm. liquid water 1º C • BUT only 0. 84 joules to raise temp. of 1 gm. rock (basalt) 1º C

Heat lost or gained = mass x change in temp x specific heat 1. Heat lost or gained = mass x change in temp x specific heat 1. How many joules to heat 10 g of liquid water 1 o C? 2. How many joules to heat 10 g of lead 1 o C? 3. Which requires the most heat energy to raise temp. from 5 o C to 10 o C: granite, dry air, lead, or iron?