Energy in Earth

1
Energy in Earths Processes

• Unit 5

2
Introduction

• Energy is the ability to do work.
• Everything in the universe involves the use or
  transfer of energy.

3
Electromagnetic Energy

• Energy given off by all matter not at absolute
  zero.
• Absolute zero- lowest possible temperature.

4
Characteristics

• Wavelength- distance from one crest to the next.
• Visible light is the only form the human eye can
  see.
• Electromagnetic E can be separated into two
  groups long-wave and short-wave
• visible light is the middle

5
E. E and the Environment

• 5 things can happen when energy hits an object
• Refracted- bent as it passes through.
• Reflected- bounces off.
• Scattered- refracted or reflected in all
  directions.
• Transmitted- passed through the material.
• Absorbed- taken into the material.

6
Absorbtion

• Surface characteristics determine amount of E E
  that can be absorbed.
• Darker surfaces can absorb more E.
• Rougher surfaces absorb more E.
• The more effective a material is at absorbing E
  E, the better it is at radiating it.

7
Transfer of E

• E moves from areas of High concentration to L
  concentration.
• Areas of highs are called sources. Areas of lows
  are called sinks.
• Thermal E- energy of the motions of atoms and
  molecules.
• Dynamic Equilibrium- a region loses and gains
  equal amounts of energy.

8
Methods of Transfer

• 3 ways
• Conduction- E is transferred from one molecule to
  another when they vibrate.
• Convection- E is transferred by movement in
  fluids.
• Radiation- E is transferred by electromagnetic
  waves.

9
Mechanical E

• All the E of an object not related to the
  individual movements of the atoms and molecules.
• Kinetic E- an object in motion.
• Potential E- stored E. The more mass that is
  involved, the more potential E.
• Potential E can be transformed into kinetic E.

10
Transformation of Electromag. Wavelength

• When E E is abosorbed and re-radiated the
  wavelength is longer than when it was absorbed.

11
Temperature and Heat

• Temperature of an object or region is directly
  related to the amount heat, or thermal E in the
  object or region.
• Temperature- the measure of the average kinetic E
  of the particles of a body of matter.

12
Heat and Thermal E

• When one object has a higher temp. than another,
  some of the E will be transferred to the cooler
  object.
• The amount of E transferred is measured in
  calories.
• Calorie- amount of heat needed to raise the temp.
  of one gram of water one degree Celsius.

13
Specific Heat

• The amount of energy it takes to bring any object
  up one degree Celsius.
• ex. Specific heat of H2O is 1
• Specific heat of a certain rock is 0.2
• Specific heat is the resistance of an object to
  heat up or cool down.

14
Heat E and the States of Matter

• An increase or decrease in the amount of E can
  cause matter to change states.
• Melting- from solid to liquid
• Solidification or freezing- liquid to solid
• Evaporation- liquid to a gas
• Condensation- gas to a liquid
• Sublimation- gas directly to a solid or from a
  solid to a gas.

15
Earths E Supply

• Some comes from Earths interior
• Most comes from the sun

16
Solar E

• Sun gives off all kinds of EE
• Greatest intensity is visible light.
• Nuclear Fusion

17
Earths E

• Most E comes from the nuclear decay of
  radioactive materials.