ENERGY TRANSFER UNIT TWO: ENERGY

WHERE DOES EARTH’S ENERGY COME FROM?  SUN

WHAT IS ENERGY?  ENERGY: The ability to do work or make change “DO WORK SUN” ENERGY

TWO TYPES OF ENERGY  KINETIC ENERGY  The energy of motion. Anything moving is considered kinetic… even waves or electricity  POTENTIAL ENERGY  The energy that is stored in something (like a ball on a hill with energy in it ready to be used when it falls downhill. Or the energy stored in food to used chemically later.

LAWS OF ENERGY (THERMODYNAMICS)  LAW OF CONSERVATION  You can’t create or destroy energy…. You can only change its form.  (energy can neither be created nor destroyed, only changed)  ONLY HAVE A FINITE AMOUNT OF ENERGY!!!!!! 

LAWS OF ENERGY (THERMODYNAMICS)  LAW OF ENTROPY  When you increase energy, you always decrease order.  Imagine a classroom full of energy.. There is no order; but a classroom with no energy lots of order! 

LAWS OF ENERGY (THERMODYNAMICS)  Absolute Zero  The coldest possible temperature is – 273 degrees Celsius.  At this temperature the atoms stop moving completely. Even the atoms in solids stop vibrating.  This is “Absolute Order” 

HOMEOSTASIS (“SAME” “STATE”  HOMEOSTASIS (same state)  Nature is like Robin Hood… it steals from the rich and gives to the poor.  Imagine a cold person hugging a warm person. The warm person who is “rich” in energy ends up giving away some of his energy to the “poor” person who has no energy.  In nature things with High Energy always give to the areas of low energy. High  Low  This occurs with heat too ( hot  cold) areas of high heat give to areas of low het.

HOW DOES ENERGY MOVE???  RADIATION  Energy Travels in Waves. (Radiates)  This is how energy can move through space from sun to the earth. Camp Fire warms you up.  This is the Electro Magnetic Spectrum (E-M spectrum)

ELECTRO MAGNETIC SPECTRUM   Long Waves Short Waves

ANATOMY OF A WAVE: DRAW AND LABEL

HOW DOES ENERGY MOVE???  CONDUCTION  Energy can travel by direct contact or touching  Imagine touching a hot pan. Your hand gets warm. The energy went straight from the pan to your hand because you touched it.  Heat moves from Warmer to cooler parts

HOW DOES ENERGY MOVE???  CONVECTION  Occurs in liquids or gasses …This is how a lava lamp works.  Transfer of heath through movement of particles.  Warm particles expand and rise, cold particles fill in the space below. This creates a circular pattern.  HOT = LESS DENSE and rise  COLD = MORE DENSE and sink 

HOW DOES ENERGY MOVE???  1. RADIATION = moves in waves  2. CONDUCTION = moves from direct contact  3. CONVECTION = Movement of particles 

RADIATION? CONDUCTION? CONVECTION? RADIATION Heat travels in waves

RADIATION? CONDUCTION? CONVECTION? CONVECTION Warm particles rise and cool fill in below

CONDUCTION, CONVECTION, RADIATION  YOU TOUCH A HOT SPOON THAT IS SITTING ON A HOT BURNER???????????  CONDUCTION – heat transferred from direct contact  A PERSON LAYS OUT IN THE SUN TO WARM UP??????  RADIATION = the heat from sun travels in waves

CONDUCTION, CONVECTION, RADIATION  A POT SITTING ON A HOT BURNER  CONDUCTION – heat transferred from direct contact  PLACING YOUR COLD HANDS OVER A CAMP FIRE TO WARM UP!  RADIATION = the heat from Fire travels in waves

CONDUCTION, CONVECTION, RADIATION  Macaroni rises and falls in boiling water????  Convection – heated particles rise and cooler fills in. Circular direction  USING A HEATING BLANKET TO GET WARM  Conduction – direct contact with your skin.

KEY POINTS TO REMEMBER  There are 3 main methods for energy transfer.  1. Radiation = waves (sun to earth like radio waves)  2. Conduction =solids, when object or molecule touch each other  3. Convection = fluids and gasses, circulation until fluid is all the same temperature

ABSORBTION OF ENERGY  THREE factors can affect how an object can absorb energy  1. Color= Black absorbs better then white  2. Surface Texture =smooth object reflect more energy and radiation than rough objects  3. Reflectivity= a shiny object reflects more energy than a dull object

SOURCES OF ENERGY  1. Electro magnetic energy= from the electromagnetic spectrum  2. chemical energy=energy released during a chemical reaction  3. Nuclear energy= energy released during fusion or fission.

ELECTROMAGNETIC ENERGY  Energy that radiates from the sun.  Electromagnetic spectrum (EMS) arranged by wavelength.  All EM waves travel at the speed of light.  Only difference between EM waves is wavelength

CHEMICAL ENERGY  Energy released during a chemical reaction.  Burning  Food during metabolism

NUCLEAR FUSION  Atoms fuse together to form a larger atom.  Results in a release of energy.  Sun  Hydrogen atoms fuse together to form a helium atom.

NUCLEAR FISSION  The splitting of an atom’s nucleus into two smaller nuclei.  Results in a release of energy.  Earth’s core  Atoms decay creating heat.

VIDEO OF FUSION AND FISSION  FISSION vs FUSION CLIP FISSION vs FUSION CLIP

HERE’S HOW IT WORKS! Energy In Temperature increases Density decreases Volume increases Pressure Decreases Energy Out Volume decreases Pressure increases Atoms move faster and get farther apart Atoms move slower and get closer together Temperature decreases Density increases

ATOMS Become excited as the added energy causes electrons to jump up an energy level They move faster and farther apart.

TEMPERATURE Is the measure of how fast atoms are moving. The more energy into the system the faster the atoms will move and the higher the temperature.

DENSITY Is the measure of the number of atoms in a given area. The faster the atoms move and the farther apart they get the fewer there will be in the same area.

VOLUME Is the space a set number of atoms occupy. The farther apart the atoms are the more space they take up.

PRESSURE Is the measure of how many atoms are pushing on a given space. The fewer the atoms on a given space the lower the pressure.

A NOTE ON PRESSURE Pressure will decrease as long as the atoms are able to move freely. If the atoms are contained the pressure will increase as they try to spread out. Think of a tea kettle and a pot of boiling water. Increased pressure Decreased pressure

EQUILIBRIUM / HOMEOSTASIS Nature wants everything to be equal and balanced. If hot and cold water are put together what happens? Nature wants everything to be equal and balanced. If hot and cold water are put together what happens? The energy is spread equally until the temperature is the same throughout. Open a bottle of perfume. Does the fragrance stay in the bottle or diffuse?

ENERGY & IT’S TRANSFER DRIVES THE EARTH SYSTEMS OCEAN CURRENTS PLATE TECTONICS WEATHER SYSTEMS RADIOACTIVE DECAY

HERE’S HOW IT WORKS! Energy In Temperature increases Density decreases Volume increases Pressure Decreases Energy Out Volume decreases Pressure increases Atoms move faster and get farther apart Atoms move slower and get closer together Temperature decreases Density increases

KEY POINTS REVIEW GET OUT A PIECE OF PAPER