Energy

By Alberto fernández fernández

What is energy

• Energy is the ability of an object to change things around it .

• Energy can be mechanical, ligth, sound, thermal, electrical, chemical or nuclear

Sources of energy• Sources can be :• Renewable : such as water , wind , sun , biomass ,

waves and tides

• Non-renewable :Fuels are sources of chemical of energy . Coal , natural gas , and petroleum are fuels .

• Uranium and plutonium are sources of thermal energy .

Energy transforms• The speakers change the electricity into sound .• The waves and tides change mechanical energy into

electricity .

Electricity • Electricity is a form of energy :• We can transport it easily through power lines .• It trasforms into other types of energy , the light

energy of a light bulb

Electrical charges • Static electricity, it occurs when an object

acumulates electrical charge .

Conducting and insulating materials• Electrical charges move easily through conducting materials

.

• Electrical charges cannot move through insulating materials like wood , rubber and plastic .

Electrical current .Electrical current is the movement of the electrical charges through a

conducting material . ELECTRIC CIRCUIT

The elements in a electric circuit are :

The generator

The conductor

The light bulb

Producing electricityHIDROELECTRIC POWER STATIONS : Use the energy from the reservoirs . Water moves a turbine and its

generates electricity

• NUCLEAR POWER STATIONS : Use uranium or plutonium to produce thermal energy

• THERMAL POWER STATIONS: Burn fuels . Combustion heats water that is converted into steam .

Steam moves a turbine and generates electricity

• WIND FARMS AND SOLAR POWER STATIONS : transform the wind and the sun energy .

Energy and the enviroment

Producing and using energy causes problems .• Changes in the landscape . The construction of reservoirs changes the landscape

• Depletion .Fuels are non-renewable sources of energy and they can run out .

• Pollution . The burning of fuels produces gases that pollute the air

Using energy efficiently

• Turn off the ligths

• Use public transport .

• Turn off the heaters and air conditioning when its possible . Insulate homes .

• Practise the 3 R `s : reduce , reuse and recycle .

Magnetism

Magnetism is the ability of materials to attract metals such as iron and steel . There are two types of magnets , natural or artificial .

Uses of magnets

• Magnets are used in door locks , bags …

• Magnetism are used to store information on credit cards

Electromagnetism

• Elctricity produces magnetism .

• Magnetism produces elctricity .

• When the wheel turns , the magnet inside the dynamo turns and it creates an electrical current .

THE END