Energy in Earth Processes 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) Major (external): the sun 2) Minor (internal): Earth’s interior

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)

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

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

Gamma rays, X rays, Ultraviolet (UV) Most dangerous Invisible 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

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

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 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? 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?

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, same

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

How does energy interact with surfaces? 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 Affect Weather

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

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

Scattering Waves refracted and/or reflected in various directions

Absorption Waves taken in by the material

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

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 absorb more or less than a rock?

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 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 with someone cold, what happens? 79

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

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

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

What are the 3 methods that energy moves by? 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 Investigation ESI Energy Scene Investigation

Convection Energy Scene #1 Identify: Where is the heat Source? Where is the heat Sink? 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 Cell (or Current) ● Circular movement Least Dense Starts to Cool Cools Down Heats Up Most Dense

Convection Cell (or Current)

Warm Up Cool Down

Conduction Energy Scene #2 Identify: 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.: Getting burnt by touching stove. Melting ice in hand. Fire poker getting hot.

Radiation 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 Good radiators = good absorbers Ex.: The Sun Light bulb Radiator

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 differences in density B. From particle to particle C. Through space or gases 1. Radiation 2. Conduction 3. Convection

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

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 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 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 (boundary) between glacier and valley walls.

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?

Temperature 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 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 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 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: 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 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 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 1o C? 2. How many joules to heat 10 g of lead 1o C? 3. Which requires the most heat energy to raise temp. from 5o C to 10o C: granite, dry air, lead, or iron?