Chapter 6

Form 1 Science Chapter 6 – Source of Energy

Chapter 6 – Source of Energy

6.1 The Various Forms and Source of Energy

1. Things have energy if they can do work. Energy is the a…………………….. to do work. 2. The unit for energy is j…………. (J). 3. Energy can exist in many different forms: working energy and stored energy.

a) Working energy: the form of energy that can involves work being done. The effects of energy c…………….. can be seen.

b) Stored energy: the form of energy is stored and can be released by c………………………. process.

A) Kinetic Energy (Tenaga Kinetik)

1. Any object which is moving possesses k……………….. e………………..2. The faster an object move, the g………………. its kinetic energy. 3. All stationary (not moving) objects have z…………. kinetic energy. 4. Kinetic energy is useful in daily life. Examples:

a) Kinetic energy of a r……………. is used to turn turbines and dynamos for generating electricity.

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Forms of Energy

Working Energy

Stored Energy

Heat energy

Kinetic energy

Sound energy

Nuclear energy

Potential energy

Chemical energy

Electrical energy

Light energy


b) Kinetic energy in w………… is used for sailing ship, turning windmills and dynamos for generating electricity.

c) Kinetic energy in an a……………………. enables it to transport passengers.

B) Potential Energy (Tenaga Keupayaan)

1. Potential energy is the energy s……………… by an object due to its p………………….. and its c…………………

2. All objects above the ground have g………………………. potential energy because of their raised position.

3. The gravitational potential energy of an object depends oni) The m…………… of the objectii) The h……………. or p………………… of the object above the groundiii) The s……………… of the gravitational pull on the object

4. The bigger the mass, the g……………….. the potential energy. 5. The higher the position of an object from the ground, the m…………. potential energy it has. 6. Potential energy is also stored in objects that can be c……………………, s………………… or bent

which called e………………. potential energy because of their stretched or compressed conditions.

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Coconut hanging on the tree The kid sitting on top of a slide A car stops at the tip of hill


C) Mechanical Energy (Tenaga Mekanik)

1. Mechanical energy is the t………….. of potential energy and k…………….. energy possessed by an object.

2. Mechanical energy is sometimes referred as d…………….. energy. 3. A falling object has mechanical energy. Half way through its fall, it has both p………………..

energy and k……………… energy.

D) Chemical Energy (Tenaga Kimia)

1. Chemical energy is the energy stored in substances such as f………….. and f…………..2. The stored chemical energy is r………………… and c………………… to other forms of energy when the

substances undergo chemical reactions.

E) Sound Energy (Tenaga Bunyi)

1. Sound object is produced by v…………………… objects. 2. Sound energy can be t……………………. from one place to another in the form of waves through a

m…………….. such as air, water or solid. 3. Sound energy travels the fastest in s…………. and slowest in g………. or a…….. This is because in

solids, molecules are very closely packed and sound energy can be transferred very fast from one molecule to another neighbouring molecule.

4. Sound energy cannot pass through a v…………….. as there are no molecules in a vacuum to transfer the energy.

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Maximum potential energy at its greatest height (No kinetic energy)

Maximum kinetic energy at its greatest speed

Food Firewood


F) Heat Energy (Tenaga Haba)

1. Heat energy is the energy found in h…….. objects. 2. The hotter the object, the m…………. energy it can give out. 3. Heat energy can increase the t………………………. of an object. 4. Heat energy is also known as t………………… energy. The heat energy that is stored in a hot

body depends on its temperature and volume. The higher the temperature, the higher the amount of heat energy that can be stored in the body.

5. The S…….. is our main source of heat energy. 6. Heat energy is s…………………. when a material burns. 7. Heat energy flows from a place or material of h……….. temperature to a place or material of

l………….. temperature.

G) Light Energy (Tenaga Cahaya)

1. Light energy is the energy radiated (spread out) by l………………… objects (objects that give out light).

2. Light energy is a kind of r………………… energy or e……………………………… radiation. 3. Light energy travels in waves and can be transmitted through v………………4. Light energy from the Sun is known as s…………… energy. 5. Light energy enables us to see things around.

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H) Electrical Energy (Tenaga Elektrik)

1. Electrical energy consists of e……………… c……………., which travel through electrical c………………… or w……………

2. Electrical energy is supplied in the form of electrical power by generators, batteries, dry cells and solar cells.

I) Nuclear Energy (Tenaga Nuklear)

1. Nuclear energy is the energy stored in the n…………………. of an atom. 2. All r……………………… materials stored nuclear energy. When radioactive materials decay,

energy is r………………… because of the changes in the nuclei of the atom. 3. Nuclear energy is also released when a particle penetrates a large nucleus and causes it to

s…………. into many smaller nuclei. This process is called n………………… r……………………4. A nuclear reactor is used to c…………….. the nuclear reaction and the energy is released. The

nuclear energy is then converted into h………… energy and the steam produced is used to generate electricity in a power station.

5. The nuclear energy generated from a nuclear reactor provides direct mechanical power to operate a s………… or a s…………………..

6. The nuclear energy is released in two ways: a) Nuclear fission (pembelahan nukleus)

A process in which a particle (neutron) penetrates a heavy nucleus and causes it to s…………. into two or more nuclei with energy released.

b) Nuclear fusion (pelakuran nukleus) A process in which light nuclei c……………… (fuse) together to form a heavier one with

energy released.

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Nucleus fission Nucleus fusion


Various sources of energy

Energy source Type of energy Energy source for daily useSun S………….. energy

H…………. energy Solar cells convert solar energy into electrical energy. Solar panels of a solar furnace absorb solar energy as heat

for heating purposes.Wind M…………………….

k……………… energy Windmills use wind power to pump water and generate

electricity.water H………………………..

energy Fast flowing water can be used to generate electric energy

for electrical equipment.Wave M……………………

k……………. energy Movement of sea waves run generators and provide

electricity.Tide G……………………..

p……………… energy Tidal barrage generates electricity.

Geothermal H…………. energy inside the Earth

Local heating. Steam is used to turn turbines and generate electricity.

Biomass (Plant and animal wastes)

B………………. energy

Food, plants, fuels for local heating. Operate machines and engines.

Fossil Fossil fuels or c…………….. energy

Thermal power station to generate electricity. Petroleum is used as the main fuel for vehicles and

machines.Radioactive substances

N…………….. energy from fission and fusion

Nuclear power station to produce electricity.

Energy Changes

1. Energy can be changed from one form to another but it cannot be c……………… or d……………….. This is known as the law of c…………………….. of energy.

2. When we use energy, we often convert it from one form to another.

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Activity Energy changesRubbing two palms together k…………….. energy → h………… energy + s…………… energyClapping k……………. energy → s…………… energyLighting a lamp c……………….. energy → e………………… energy → l…………… energy + h…………

energyReleasing a stretched spring p……………….. energy → k……………. energyHeating the joints of a copper and a zinc wire

c……………….. energy → h……….. energy → e…………….. energy → k…………….. energy

Lighted candle c……………….. energy → h………… energy + l…………. energyAlarm clock p……………… energy → k……………… energy → s……………. energyBicycle dynamo k……………… energy → e………………. energy → h……… energy + l……………

energyTelevision e………………. energy → l………… energy + s…………… energyMoving car c………………. energy → k…………….. energy

6.2 Renewable and Non-renewable Energy Sources

1. Energy resources can be divided into two main groups: r………………… and n……………………………

2. Renewable energy sources are the energy sources that can be r……………….. after being used. (eg. solar energy)

3. Non-renewable energy resources are energy sources that c…………….. be replaced after being used. They will run out eventually. (eg. petrol).

Renewable energy sources

1. Wind energy a) Wind power is used to turn the blades of large windmills or generators to p………………

electricity or to p……….. water out of the ground. A high wind speed is needed to power wind generators effectively.

b) Wind generated electricity does not cause air pollution. However, it costs more to produce than the electricity generated from coal.

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Sources of Energy

Non-renewable energy sources

Renewable energy sources

Wind Tidal / wave energy Biomass Hydroelectricity Geothermal energy Solar energy

Fossil fuel Radioactive substances (nuclear

energy)


2. Tidal / wave energy a) A dam or barrage is built across a river mouth or estuary. Electricity is generated by the

flow of water through turbines in dam as the tides rise and fall. b) Waves are caused by wind and partly by the tides. The rapid u……………………….

movement of waves on the surface of the sea can also drive turbines to produce electricity.

3. Biomass energya) Biomass is plant and animal waste materials that can be used for generating electricity.

This includes using fuel made from sugar cane, biogas of rotting waste and manure of livestock.

b) M……………….. gas from biomass is used to generate electricity. c) Converting biomass energy into usable energy has many environmental benefits.

- Fuels such as alcohol that made from biomass is used as alternative to p…………….. to power motor cars.

- Solve the problem of waste disposal and at the same time c…………… energy for use at homes, farms and factories.

Biomass energy hydroelectric energy

4. Water power – hydroelectric energy a) Hydroelectricity is produced from the k…………….. energy of water. The movement of the

water spins turbines which generate electricity. b) Locations with high rainfall and steep mountains are ideal for hydroelectricity. The

largest hydroelectric power plant in Malaysia is in Kenyir Lake. c) Most electricity projects require the building of large d……… across the rivers. d) The use of hydroelectricity energy does not cause pollution but the building of large

dams effects the ecosystems of the surrounding area. 5. Geothermal energy

a) Geothermal energy uses the h………… energy from beneath the surface of the earth. Hot spring, geysers and volcanic eruptions shows that the earth is very hot deep inside it.

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b) The steam is used to heat houses and factories, and drive turbines and dynamos to produce electrical energy.

c) Geothermal energy is a good source of energy because it is clean and can be extracted without burning fossil fuels.

6. Solar energy a) Solar energy is energy from the S……..b) Solar energy is used for heating water, cooking and producing electrical energy. c) Solar cookers and heaters convert solar energy to h……….. energy. d) Solar cells convert solar energy to e…………………. energy. e) Green plants use solar energy to make food then store it in the food as c…………….

energy.

Non-renewable energy sources

1. Fossil fuelsa) Three major fossil fuels: c……………, p………………… and n…………………..b) They are called fossil fuels because they are formed over millions of years from the

fossils and remains of dead animals and plants. The fossils are buried under dirt and rock. Heat and pressure from the earth cook them into oils, natural gas.

c) Coal - Most abundant fossil fuel resource. It is hard, black, rock-like substance. - Mainly burned in power stations to generate electricity and as a source of heat for

industry. d) Petroleum

- A very important source in modern times. - It contains many types of fuel such as aviation fuel, petrol, kerosene and diesel.

e) Natural gas - Used as cooking fuel. - It can be liquefied and stored in cylinders. It is also piped to houses and factories for

use. 2. Nuclear energy

a) Nuclear energy is obtained by s………………… the atoms of u………………. and p………………..b) The splitting of the atoms is done by a controlled way in a reactor. c) The heat energy released is used to produce steam under high power. The steam is used

to drive turbines and dynamos to produce electrical energy.

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6.3 The Importance of Conserving Energy Resources

The need to conserve energy

1. Energy sources contribute towards the development of a country. 2. Energy sources from fossil fuels and nuclear energy are l……………… and one day will be used

up. 3. Hence, we must conserve these energy sources as that they can last as long as possible. 4. There are two main ways of conserving energy sources.

a) Not to waste energy obtained from fossil fuels and nuclear energy because they are non-renewable.

b) Look for alternative sources of energy such as to replace the renewable sources. - Solar energy- Wind- Energy from waves and tides- Energy form biomass

The use and management of energy resources

1. S…………………………..a) Gas stove must be turned off after used. b) Lights and fans must be switched off after used.

2. I……………… e………………………a) The efficiency of electrical appliances should be improved. (Eg. the filament bulb is not

efficient because it wastes a lot of electrical energy in the form of heat). 3. R……………….. e………………………. p……………………

a) Prevent poor combustion from the vehiclesb) Fossil fuels such as coal must be used in great care because they can produce pollutants

such as acidic gases, soot and dust. c) Uranium and plutonium can pollute the environment with unseen dangerous radiations

which can be fatal. 4. Use a………………………. energy resources such as biomass, wind, solar, tides and hydro energy.

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Chapter 6