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4-19-13 FRIDAY!
• Do Now: Do eclipse worksheet. Both sides.
• LT: I can describe how energy is transformed from one form to another (PS3A).
Types of energy
Moving (kinetic) energy
• Light
• Thermal
• Electrical
• Mechanical
• Sound
Potential energyPotential energy•ChemicalChemical•GravitationalGravitational•ElasticElastic•NuclearNuclear
Energy Transfer
EfficiencyAn energy diagram for the bike would look like this :-
100 000 J
Chemical Energy
80 000 J
Kinetic
12 000 J Heat
8 000 J Sound
Insulation
What’s in The Box?
Energy in:
Electrical energy
Energy out:
Sound energy
What’s in The Box?
Energy in:
Electrical energy
Energy out:
Sound energy A radio converts
electricity into sound
What’s in The Box?
Energy in:
Electrical energy
Energy out:
Heat energy
What’s in The Box?
Energy in:
Electrical energy
Energy out:
Heat energy A cooker converts
electricity into heat
KS3 stuff!
What’s in The Box?
Energy in:
Electrical energy
Energy out:
Light energy
What’s in The Box?
Energy in:
Electrical energy
Energy out:
Light energy A lamp converts
electricity into light
KS3 stuff!
What’s in The Box?
Energy in:
Chemical energy
Energy out:
Heat & Light
energy
What’s in The Box?
Energy in:
Chemical energy
Energy out:
Heat & Light
energy
A match converts chemical energy
into light and heat
KS3 stuff!
What’s in The Box?
Energy in:Energy out:
Heat Energy
Electrical energy
Light Energy
What’s in The Box?
Energy in:Energy out:
Heat Energy
Electrical energy
Light Energy
Although a lamp is meant to transfer electrical energy into light it actually
transfers most of the energy into wasted heat.
Energy Transfer
Energy chains
Exit
1. Write the LT in your own words.
2. What was the most important thing you learned today?
3. What are still the most unsure about?
• Sun> light energy>wheat>chemical energy>breakfast>mechanical energy>ride bike up hill>gravitational potential energy>coast downhill>kinetic energy>crash into tree>sound energy>leaves shake/windows rattle>
Video• Matter? Everything in the Universe. Solid-liquid gas.• Matter needs energy to change.• Energy constantly changing• Never created/destroyed• Energy can be transferred• Work: force working over a distance to move an object. A transfer of energy.
Also needs energy! • …stacking boxes. Potential changed to kinetic• Potential energy: Position—spring (elastic)—• Law of conservation of mass and energy—Einstein—
– Ping pong/golf ball– Heat transfer. Conduction, convection, radiation
•
EfficiencyIn any energy change there is ALWAYS wasted energy
•When a zebra eats the grass, it does not obtain all of the energy the grass•When a lion eats a zebra, it does not get all of the energy from the zebra
•Only 10% of the energy from one trophic level is transferred to the next – this is called the 10% law