Energy

LIGASEElementary School Physics

Table of ContentsEnergy Types &

Conversions

Magnetism

Electricity

Sound

Light

PE & KE Heat

ENERGY

• Definition:

the ability to cause a change.

Types of Energy

• Heat - the motion of molecules

• Mechanical - motion of objects

• Sound - vibration

• Chemical - chemical reactions

• Light - visible and invisible waves

• Electrical - electricity & magnetism

Conservation of Energy

• Definition: energy cannot be created nor destroyed, but can be transferred from one form to another.

Energy Transfers• One form of energy can turn into another form.

For example: – A ball thrown against the wall represents

mechanical energy. The ball does not bounce back at the same speed, in part, because some of the mechanical energy is converted to sound and heat

Energy Transfer Activities

• Bring in different toys and household items that illustrate multiple energy transfers. Have students identify each energy in the toy/item.

• Most energy that is “wasted” in an energy transfer is converted to heat.


• Batteries (chemical)

• Electricity (electrical)

• Motor turns (mechanical)

• Motor makes noise (sound)

• Motor gets warm (heat)

• Wheels turn (mechanical)

• Friction on the floor (heat)


Jack-in-the-Box

Now you identify the

energy transfers.


Wind-up Mouse

Identify the

energy transfers.


• Have students make “Rube Goldberg” drawings illustrating multiple energy transfers. Each drawing should include a number of tasks leading up to a final goal (ex. making toast).

Potential Energy

• The energy stored in an object.

Gravitational Potential Energy• The stored energy of position.

• Weight (N) = mass (kg) x gravity (9.8 m/sec/sec)– 100 kg x 9.8 m/sec2 = 980 N

• GPE = weight x height– 980 N x 10 m = 9,800

10 m

100 kg

Kinetic Energy

• The energy of motion.

• KE = (m x v2) / 2– (100 x 52) / 2 = 1,250

100 kg

Average Velocity5 m/sec

Pendulum Potential Kinetic

100% PE

100% KE

50% PE

50% KE

Energy

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Transcript of Energy