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