Topic 5: Energy and Earth Processes

Energy Transfer Learning Objectives

• Describe the difference between kinetic and potential energy and give one real-life example of each.

• Describe the three ways energy is transferred between objects.

• Give at least one real-life example for each type of energy transfer.

• Explain how electromagnetic energy travels.• Explain how types of energy are different apart.• Give examples of materials which make the best absorbers

and reflectors of energy.

Temperature Learning Objectives

• Convert temperatures between the three temperature scales.• Describe the relationship between temperature and

molecular motion.• Describe absolute zero in terms of molecular motion.

Temperature Learning Objectives

• Explain the concept of specific heat in your own words and with real-life examples.

• Use the ESRTs to predict which earth materials will heat the fastest or slowest based upon their specific

• heats.• Identify that water (liquid) has the highest specific heat of any

Earth material.• Explain why, in terms of specific heat, materials that are good

absorbers are also good radiators.

Heating of Water Learning Objectives

• Correctly label the water heating graph with the following characteristics: freezing, melting, condensing, and evaporating.

• Identify when heat is being gained or lost by water on the water heating graph.

• Explain which phase changes require the biggest gains/losses of energy for water.

• Calculate the rate of temperature change for water.

Energy: The ability to do work

Earth’s two Heat Engines

1) External: The sun drives surface processes

Effects: Wind patterns and ocean currents

2.) Internal: Decay of radioactive elements

Effects: Plate tectonics

Electromagnetic Energy

Form: Energy that travel in the form of waves

Characteristics

Wavelength: Distance from crest to crest

What is the name given to different types of radiation?

Electromagnetic radiation

Interactions Between Electromagnetic Energy and the Environment

1) Refraction: Waves are bent due to density differences

2) Reflection: Light waves bounce off of materials

3) Scattering: Waves are reflected and refracted in all directions

Explanation

4) Transmitted: Light waves are able to pass through

5) Absorbed: Light waves are taken into the material and turned to heat

Surface Properties of Absorption

Color: Dark absorbs and light colors reflect

Texture:Rough absorbs and Smooth reflects

Relationship between absorption and radiation:

Good absorbers of radiation are also good radiators!!!!!!

Transfer of Energy

Direction of energy transfer: Always goes from high to low

Achieving Dynamic Equilibrium: Heat is transferred until temps. are equal

Types of Energy Transfer

1) Conduction: Energy moves from direct contact of particles

Materials: Most often with solids

Eureka

2) Convection: Transfer of energy due to density differences

Materials: Only occurs in fluids (liquids and gasses)

Where does it occur? Atmosphere and bodies of H2O

Eureka

3) Radiation:

Material:

The transfer of energy in the form of waves

No medium necessaryThe more energy an object has the more it gives off!!!

Eureka

Transformation of Mechanical Energy

Mechanical Energy: The total kinetic and potential energy in a system

Kinetic Energy: The energy of motion

Potential Energy:

Mass and velocity

Factors of P.E.:

Stored energy

Factors of K.E.:

Mass and position

Transformation of P.E. to K.E.

Transformation of Electromagnetic Radiation

What is the relationship between temp. and wavelength of light that is radiated? Smaller Wavelength = More Energy

Does the sun radiate shorter or longer wavelengths of light than earth ? Shorter (Sun emits UV and Visible)

Which wavelength of light is radiated from earth? Infrared

Can This Be A Problem ????

Greenhouse Doom and Gloom

Temperature and Heat

Kinetic theory of matter: All matter is made of atoms that are moving

What is the relationship between kinetic energy and temp.?

Temperature: Average kinetic energy of a system or object

Direct

Heat and Thermal Energy

Hot: Energy leaves the object and goes to body

Cold: Energy leaves the body and goes to object

Calorie: Energy needed to change the temperature of one gram of water 10 c

Liquid water has a higher specific heat than any other natural substance!!!!!!!!!

Heat Energy and Changes in State

Melting: Solid to liquid

Sublimation:

Freezing: Liquid to a solid

Solidification: Liquid to a solid

Evaporation: Liquid to a gas

Condensation: Gas to a liquid

Solid directly to a gas

Precipitation: Gas directly to a solid

Notice what Happens to Temperature

Temp. increases (molecules move faster)From -100 to 0:During melting: Bonds break (334 J/g used)

0-100: Temp. of liquid water increasesWater being liberated (2260J/g used) During Vaporization:

100 to 200: Temp. of gaseous water increasing

Earth’s Energy Supply

Most Intense:

Solar Energy

Visible and Ultraviolet

Shortest wavelength (UV=sunburn)

Wave lengths:

Nuclear FusionWhat Produces Solar Energy:

Secrets of the Sun

Earth’s Own Energy

1) Remains from when earth first formed

2) Materials that are under extreme pressure

3) Radioactive decay of elements

Overwhelming