elina (sains)
TRANSCRIPT
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CHAPTER 6:
Sources Of Energy
NAME : Nor Elina Fazlin Bte Mohd Osman
CLASS : 1T
TEACHER NAME : Shirley Teoh
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6.1 : Various Forms and Sources of Energy
Forms of Energy
Energy is definied as the ability to do work .
For example , energy is required to run , climb a tree , light a bulb , ride a bicycle ,
and row a boat .
All living things need energy to conduct daily activities .
Man and animals obtain energy from food which are in turn obtained from plants
or other animals .
Plants obtain energy from food manufactured during the process of
photosyhthesis .
Energy in measured injoules (J) .
Energy is found in many forms :
(a) Kinetic energy
(b) Potential energy
(c) Heat energy
(d) Light energy
(e) Sound energy
(f) Chemical energy
(g) Electrical energy
(h) Nuclear energy
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- Kinetic Energy
Kinetic energy is present in object that are moving .
The kinetic energy of an object increases when it moves faster . Examples of kinetic energy :
(a)a moving car
(b)a flying bird
(c) swinging pendulum
A moving car A flying bird
Swinging pendulum
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- Potential Energy
Potential energy is stored in a body due to its position (gravitational potentialenergy) or its physical state (elastic potential energy) .
The gravitational potential energy of an object depends on the mass of the object ,the distance of the object from the Earths surface and the power of the gravitational
pull on the object .
Elastic potential energy exists in only elastic substances such as a spring or rubber .
Examples of objects which have elastic potential energy is a wound-up spring of a
toy car , a stretched rubber band and a compressed spring .
Stretched rubber band A stretched cord of a bow
An object gains potential energy as it gains height
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- Heat Energy
Heat energy is the energy that is stored in a hot object .
The heat energy of a body depends on its temperature and volume .
Heat energy can be detected by our skin .
Examples of sources of heat energy :
(a)Fire
(b)Sun
(c) Hot spring
(d)Boiling water
(e)Electrical heater
Fire Sun
Hot Spring
Boiling Water
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- Light Energy
Light energy is the energy produced by an object that emits light .
Light energy can be detected by the eye . without light , the eye cannot seesurrounding object .
Green plants use light energy from the Sun to carry out photosynthesis .
Sources of light energy :
(a)Sun
(b)Fire
(c) Lightning
(d)Lamp / bulb
Sun Fire
Lamp
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- Sound Energy
Sound energy can be detected by our ears .
Sound energyis produced when we talk , sing , whistle , knock something , clap
or play musical instruments .
Sound energy is important because it enables us to communicate and have
entertainment .
Examples of object which can produce sound energy :
(a)Striking a drum
(b)Ringing a bell
(c) Plucking at a guitar
(d)Scraping a violin
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- Chemical Energy
Chemical energy is the energy stored in a chemical substance .
Chemical energy is found in fuels such aq petroleum , methane gas , candle ,coal , and wood ; food such as rice , meat , fruits , and maize .
Examples of chemical energy :
(a)Food
(b)Dry cell
(c) Candle
(d)Wood
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- Electrical Energy
Electrical energy is the energy produced by the flow of electric charges .
Electrical energy is supplied in the form of electric power , which is thenconverted into other forms of energy to perform work .
Examples of electrical energy :
(a)A dynamo
(b)A battery / dry cell
(c) A solar cell
(d)An electric generator
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- Nuclear Energy
Nuclear energy is obtained from elements such as plutonium and uranium .
Nuclear energy is mostly used to generate electricity .
Nuclear energy is also known as atomic energy .
Some ships and submarines are powered by nuclear energy .
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Sources of Energy
There are various natural sources of energy on Earth .
Almost all the energy sources on Earth originate from the Sun .
These sources of energy are used by man either directly or through energy
converters .
Types of energy sources on Earth :
Fossil fuels such as petroleum , natural gas and coal .
Water in mountain areas used to generate hydroelectrical energy .
Heat from inside the Earth also known as geothermal energy .
Wind used to generate electrical energy .
Waves used to generate electrical energy .
Animal and plant materials also known as biomass fuels .
Radioactive metals used to produce nuclear energy . The Sun main sources of heat and light energy .
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- Fossil Fuels
Fossil fuels are fuels formed from remains of plant and animals buried in the
ground and which had decomposed million years ago .
Green plants use light energy from the Sun to make food .
Coal , petroleum , and natural gas are examples of fossil fuels .
- Biomass Fuels
Biomass fuels are obtained from decomposed organisms such as plants andanimals .
Examples of biomass fuels :
(a)Stems , branches , twigs , dry leaves , and fruits of plants .
(b)Oils and fats of animals
(c) Decomposed plant wastes and animal remains .
(d)Animal wastes .
- Wind
Wind is formed when there is a difference in air pressure between two places .
The difference in air pressure is caused by the Sun .
Wind as a source of energy can be traced back to the Sun .
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The Change of Energy
The principle of conservation of energy states that :
(a)Energy cannot be created or destroyed .
(b)Energy can only be transformed , or changed from one form to another .
Therefore , to use energy means to change one form of energy to another form of
energy that can perform a useful function .
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6.2 : Renewable and Non-renewable Energy Sources
There are two groups of sources of energy available : the renewable and non-renewable .
Most of the energy resources used by human are non-renewable .
- Renewable Resources
Renewable energy sources are energy sources that can be replaced when they
have been used . This means that the supply of these energy sources will not be used
up .
- Non-renewable Resources
Non-renewable energy sources are energy sources that cannot be replaced and
will finally be used up .
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6.3 : The Importance of Conserving Energy Sources
The non-renewable energy resources on Earth are slowly depleting because ofcontinuous and widespread usage .
We can show our appreciation by using the energy sources that we have today
wisely and not in wasteful ways to make sure that these energy sources are still
around for future generations to use .
We should use and manage energy sources carefully . For example , we can :
practise car-pooling or use public transport ,
switch off electrical appliances when they are not in use ,
turn off water tap when they are not in use ,
practise recycling of materials ,
practise reuse of materials .
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One Direction what makes you beautiful .
You're insecure
Don't know what for
You're turning heads when you walk through the door
Don't need make up
To cover up
Being the way that you are is enough
Everyone else in the room can see it
Everyone else but you
[Chorus]
Baby you light up my world like nobody elseThe way that you flip your hair gets me overwhelmed
But you when smile at the ground it aint hard to tell
You don't know
You don't know you're beautiful
If only you saw what I can see
You'll understand why I want you so desperately
Right now I'm looking at you and I can't believe
You don't know
You don't know you're beautiful
Oh oh
But that's what makes you beautiful
So c-come on
You got it wrong
To prove I'm right I put it in a song
I don't why
You're being shyAnd turn away when I look into your eyes
Everyone else in the room can see it
Everyone else but you
[Chorus]
Baby you light up my world like nobody else
The way that you flip your hair gets me overwhelmed
But you when smile at the ground it aint hard to tellYou don't know
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You don't know you're beautiful
If only you saw what I can see
You'll understand why I want you so desperately
Right now I'm looking at you and I can't believe
You don't knowYou don't know you're beautiful
Oh oh
But that's what makes you beautiful
[Bridge]
Nana Nana Nana Nana
Nana Nana Nana Nana
Nana Nana Nana Nana
Baby you light up my world like nobody else
The way that you flip your hair gets me overwhelmed
But you when smile at the ground it aint hard to tell
You don't know
You don't know you're beautiful
[Chorus]
Baby you light up my world like nobody elseThe way that you flip your hair gets me overwhelmed
But you when smile at the ground it aint hard to tell
You don't know
You don't know you're beautiful
If only you saw what I can see
You'll understand why I want you so desperately
Right now I'm looking at you and I can't believe
You don't know
You don't know you're beautifulOh oh
But that's what makes you beautiful