sources of energy f1

8/3/2019 Sources of Energy f1

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Energy- ability to do work

Light energy:

- enables us to see things

- green plants use light energy from the Sun to carryout photosynthesis

VARIOUS SOURCES OF

ENERGY


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Kinetic energy:

- present in objects that are moving- increases when it moves faster

- ex: a moving car, a flying car, a swinging pendulum


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Potential energy:

- Types: Gravitational potential energy and elasticpotential energy

i) Gravitational potential energy

- Energy stored in an object when the object is raised from

its position


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- The higher an object is from the ground, the bigger thepotential energy. Ex: a person climbing up a

staircase/mountain


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ii) Elastic potential energy

- Stored in objects that are compressed, stretched or bent.

Ex: a stretched rubber band, a compressed spring, astretched cord of a bow, a bent ruler.


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Sound Energy

- Can be detected by our ears.

- Produced when we talk, sing, whistle, knock something,clap, or play musical instruments.

- Important in communicating, having entertainment, alertpeople of something. Ex: ring the bell when we want the

bus to stop


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Heat energy

- Can be detected by our skin

- Burning of fuels i.e. petrol, coal and firewood


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Electrical energy

- The form of energy that makes things function

- Ex: home appliances


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Chemical energy

- Energy stored in substances i.e. food, fuels, chemicals


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Nuclear energy

- Obtained from plutonium and uranium- Used to generate electricity. Ex: ships and submarines-

powered by nuclear energy


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Fossil fuels- petroleum, natural gas, coal

Water in mountain areas- used to generatehydroelectrical energy

Heat from inside the Earth- geothermal energy Wind- generate electrical energy

Waves- generate electrical energy

Animal and plant materials- biomass fuels

Radioactive metals- produce nuclear energy The Sun- main sources of heat and light energy

SOURCES OF ENERGY


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Fossil fuels- formed from plants and animals that diedmillions of years ago

Biomass fuels- obtained from plant and animal materials

Generation of hydroelectrical energy depends on heavyrainfall in mountain areas. Heat energy of the Sun causeswater to evaporate and form clouds. Cloud condenses toform rain

Wind- formed when there is a difference in air pressurebetween two places (caused by Sun).

Waves- from the wind that blowing across the sea

Geothermal energy and nuclear energy- metals

THE SUN AS THE PRIMARY

SOURCE OF ENERGY


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Renewable energy sources

- energy sources that can be replaced when they havebeen used

- the supply of this energy sources will not be used upEx; wind, geothermal, sun, waves, biomass, water

Non-renewable energy sources

- energy sources that cannot be replaced- finally be used up

Ex; petroleum, natural gas, coal (fossil fuels) andplutonium, uranium (radioactive metals)

RENEWABLE AND NON-

RENEWABLE ENERGY


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Why do we need to conserve energy?

- natural gas, petroleum, coal- limited, will be finally usedup

How?

- develop more efficient engines of motor vehicles andmachines

- make sure that engines of motor vehicles are servicedregularly and are in good condition

- switch off electrical appliances when not in use

Use fluorescent lamps which are more energy-efficient

instead of filament lamp.

THE IMPORTANCE OF


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Use energy wisely and not in wasteful ways

Use and manage energy sources carefully

Ex:

- practise car-pooling/use public transport - switch off electrical appliances when they are not in use

Turn off water taps when they are not in use

- practise recycling of materials

- practise reuse of materials

THE IMPORTANCE OF

CONSERVING ENERGY

SOURCES

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