Energy
Energy is all around us.
Energy Transfer vs. Energy Transformation
*NOTE
* NOTE
The Law of Conservation of Energy
The Law of Conservation of Energy - Energy is never created or destroyed!
• The total amount of energy will always remain the same!
*NOTE
TYPES OF ENERGY
TWO MAIN CATEGORIES -->
Potential (Stored) and Kinetic (Motion)
NOW, on to the different (smaller) categories….
*NOTE
What is Mechanical (Motion) Energy?
Energy due to an object’s motion (kinetic).
The bowling ball has motion energy.
When the ball strikes the pins, motion energy is transferred to the pins!
Sound energy would fit here...
*NOTE
What is Sound Energy?
A type of mechanical energy due to the vibrations of particles
-Sound waves travel through matter (solid, liquid, or gas) ...how is this different from radiation?
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What is Electromagnetic Energy (Radiation)?
Energy that moves in waves through a medium or space---
Light energy but also includes...
energy from gamma rays, x-rays, ultraviolet rays, visible light, infrared rays, microwave and radio waves
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What is Electrical Energy?
Energy caused by the movement of electrons
Easily transported through power lines and converted into other forms of energy
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What is Thermal Energy?
Heat energy (conduction, convection, radiation)
The heat energy of an object determines how active its atoms are.
A hot object is one whose atoms and molecules are excited and show rapid movement.
A cooler object's molecules and atoms will show less movement.
*NOTE
What is Chemical Energy?
Energy that is stored in materials and available for release from chemical reactions.
The chemical bonds in a matchstick store energy that is transformed into thermal energy when the match is struck.
Food, batteries, and gasoline are examples.
*NOTE
What is Elastic (Stored Mechanical) Energy ?
Energy that is stored in objects when they are stretched, compressed, twisted or bent.
Rubber bands, trampolines, metal springs are all examples.
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What is Gravitational Potential Energy?
Energy due to position.
Examples include water on a waterfall, sleds at the top of a hill...
*NOTE
What is Nuclear Energy?
Stored in the center of an atom: the nucleus. When a nucleus is divided or combined with another nucleus, this potential energy becomes one of the most powerful forces in the universe.
Energy Transfer
The process of transferring energy from one object to another. It does not change form, it just moves.
Ex: Heat can be transferred from hot water to cold water just by connecting the two with a piece of wire.
*NOTE
Energy Transfer
Activity: Ice melting in hand
Form = HEAT (thermal)
Source = hands
Receiver = ice
Activity: Biking
Form = KINETIC or MECHANICAL (Motion)
Source = legs
Receiver = bike
Activity: Feeding frog
Form = CHEMICAL
Source = grasshopper (food)
Receiver = Frog (growth)
*NOTE
Energy Transfer
Using Electronics
Form = ELECTRICAL
Source = outlet
Receiver = appliance (TV, computer)
Seeing light
Form = LIGHT
Source = mirror
Receiver = eye
Hearing Music
Form = SOUND
Source = drum
Receiver = ear
*NOTE
Intended vs. Unintended Energy (Intentional vs. Unintentional)
Intended energy - the energy transfer that happens on purpose
Unintended energy - energy transfer that is not on purpose
Energy Transformation
• Energy transformation is the process of changing energy from one form to another.
Energy Can Be Transformed
Transformation = converting one form of energy to another form of energy
Energy Transformation
Electrical energy is transferred from the wall socket to the computer. Choose the best answer below showing the transformation from electrical to...
A. Sound and heat
B. Light and heat
C. Light and chemical
D. There is no transformation
Electrical energy is transferred from the wall socket to the curling iron. Choose the correct transformations that occur when Electrical energy is transformed in this picture....
A. Electrical to light
B. Electrical to sound
C. Electrical to chemical
D. Electrical to Heat
Light energy from the sun is transformed to ________ in the leaves as the plants grow. Choose the best answer
A. Light
B. Electrical
C. Chemical
D. Heat
The apple on the tree has gravitational energy due to its position. Gravitational energy is transformed into _______energy as the apple falls and hits the man’s head.
A. Light
B. Motion
C. Sound
D. Heat
Energy Chain Diagrams
• A method used to show the energy transfers or transformations taking place in a system
Energy Accounting Diagram
• Diagram show the flow of energy into and out of a system
http://www.teachersdomain.org/asset/tdc02_int_energyflow/
QUIZ TIME!
QUIZ TIME!
QUIZ TIME!
Electrical energy is transported to your house through power lines.
When you plug an electric fan to a power outlet, electrical energy is transform into what type of energy?
MECHANICAL ENERGY
QUIZ TIME!
What energy transformation occurs when an electric lamp is turned on?
ELECTRICAL ENERGY
↓
ELECTROMAGNETIC ENERGY
What types of energy are shown below?
Mechanical and Thermal Energy
(Don’t forget friction)
What type of energy is shown below?
Chemical Energy
What types of energy are shown below?
Electrical, Mechanical and
Electromagnetic Energy
What type of energy is shown below?
Chemical Energy
What type of energy is shown below?
Thermal Energy
Energy Transfer
Chemical
Electrical
Electrical
Electrical
Sound
(mechanical)
Light
(Electromagnetic)
Thermal
Mechanical
Get Started! OUTLINE
Energy Demo
• What energy transfer is taking place in the demonstration?
• What energy transformations are taking place in the demonstration?