Energy

ENERGYENERGY

It is the ability to do work.Energy is always changing.

We can’t create energy.We can’t destroy energy.We can only transform energy.

EnergyEnergy

FORMS OF ENERGYFORMS OF ENERGY

Forms of energyForms of energy

Thermal energy

Electrical energy

Kinetic energy

Light energy

Chemical energy

Heat energyHeat energy A hot object or substance passes its heat to something else which is colder.

Electrical energyElectrical energyMany thinngs we use everyday work

with electrical energy. Lightnings, during a storm, produce

electrical energy.

Kinetic energyKinetic energy Anything moving has kinetic energy.

Light energyLight energyAnything that has light has

light energy

Chemical energyChemical energy

It is stored in:

Fuels: Wood Petrol

Gas Coal

Food (living things):

The energy is released when the object

which contains it is burnt.

LIGHT ENERGYLIGHT ENERGY

Light sourceLight sourceIt is anything which emits light.

Natural: It is not created by man.

Artificial: It is created by man.

Properties of lightProperties of light

It moves in a straight line.

It moves in all directions.

It travels very fast.

It interacts with the objects it reaches. Light can be reflected, absorbed or it can pass through the object.

Phenomena of light.Phenomena of light.Shadow: It is the dark area formed behind an opaque

object when it blocks the light.

Composition of light: It is a mixture of 7 different colours, but we

see it as white.

SOUND ENERGYSOUND ENERGY

SOUND ENERGYSOUND ENERGYAnything that makes a sound has sound

energy.Sound is produced when objects vibrate.

It travels in waves and in all directions.It also travels very fast but not as fast as

light.

SOUND ENERGYSOUND ENERGYSound can travel through air and water.

Unlike light it can travel through opaque objects.

Like light, sound can reflect off some objects. When this happens we can hear an echo.

ENERGY ENERGY SOURCESSOURCES

Energy sourceEnergy source

It is the material or phemomenum we obtain energy from

Energy sources:Energy sources:

Renewable: It does not run out. It does not cause pollution.

Non-renewable: It will run out. It causes pollution.

EFFICIENT USE OF EFFICIENT USE OF ENERGYENERGY

The efficient use of energyThe efficient use of energyWe must use less non-renewable energy,

because it pollutes The Earth and it can run out.

We must use more renewable energy, because it does not pollute and it does not run out.

We must save energy by:

◦ Using more efficent motors.

◦ Avoiding unnecessary consumption.

◦ Recycling, reducing and reusing materials. (3 R’s)

◦ Use energy saving light bulbs