Lss module 1 chpt 2 investigating energy

1. MODULE 1:
GADGETS WORK WONDERS (I)
Chapter 2 Discovering Energy
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2. Chapter 2 Discovering Energy
2.1 What are the different forms of
energy?
2.2 How can energy be converted from
one form to another?
2.3 What are the differences between
renewable and non-renewable
energy?
2.4 How can energy be used
responsibly?
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3. Objectives
 Recognise and give examples of
different forms of energy in everyday
life (potential energy, kinetic energy,
light energy, heat energy, electrical
energy and sound energy)
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4. What is energy?
 Energy is the ability
to do work.
 There are many forms
of energy.
Examples are:
(a) potential energy
(b) kinetic energy
(c) light energy
(d) heat energy
(e) electrical energy
(f) sound energy
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Different forms of energy
light energy
kinetic energy

5. What is potential energy?
 Potential energy is stored energy.
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Different forms of Potential Energy
water at the top of a waterfall has
gravitational potential energy
black petroleum contains useful
chemical potential energy
the stretched spring in a
stapler has elastic potential energy

7. What is kinetic energy?
 Kinetic energy is the energy that moving objects
have.
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moving objects have kinetic energy

8. What is light energy?
 Light energy allows us to see things.
 Light energy also plays an important role of helping
plants make food through photosynthesis.
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light helps plants to make food and the
table lamp provides light for reading.

9. What is heat energy?
 Heat energy keeps us warm in a cold environment
and helps us cook our food.
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Heat is needed to toast bread and for
keeping warm beside a fireplace

10. What is electrical energy?
 Electrical energy is the
result of the movement of
electrons in electrical
conductors such as
copper wires.
 Electrical energy is a very
useful and convenient
form of energy used
widely in our daily lives. It
is useful because it can be
converted easily to other
forms of energy by using
electrical appliances.
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Electric hob
(converts electrical
energy to heat energy)
Light bulb
(converts electrical
energy to light energy)

11. What is sound energy?
 Sound energy allows us to
hear and communicate.
 Sound energy enables us to
listen to our favourite music
and hear warnings of
danger.
 Sound is produced by
vibrating objects such as
the speaker in an electronic
alarm clock or a hand bell.
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Activity Book Link
Activity 2.1
Discovering Energy
hand bell (converts
kinetic energy to
sound energy)
electronic alarm clock
(converts electrical energy to
sound energy)

12. Chapter 2 Discovering Energy
2.1 What are the different forms of
energy?
2.2 How can energy be converted
from one form to another?
2.3 What are the differences between
renewable and non-renewable
energy?
2.4 How can energy be used
responsibly?
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13. Objectives
 Investigate energy conversion from
one form to another
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14. Law of Conservation of
Energy
 Energy cannot be created or
destroyed. It can only be converted
from one form to another.
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shooting an arrow with
a bow converts elastic
potential energy to
kinetic energy
a wind generator
produces electricity
from the kinetic energy
of wind
using an electric bulb
converts electrical
energy to light
energy

15. Useful energy conversions
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using batteries as a
source of electricity
converts chemical
potential energy to
electrical energy
fossil fuels contain chemical energy
which can be converted to
electrical energy
audio-visual
equipment converts
electrical energy to
sound and light energy

16. Harmful energy conversions
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a nuclear explosion
converts nuclear energy to
heat energy
overheating of wires can cause fire as
electrical energy is converted to heat energy
loud noises from
jackhammer can cause
hearing loss as kinetic
energy is converted to
sound energyActivity Book Link
Activity 2.2
Steam Engine Model

17. Chapter 2 Discovering Energy
2.1 What are the different forms of
energy?
2.2 How can energy be converted from
one form to another?
2.3 What are the differences between
renewable and non-renewable
energy?
2.4 How can energy be used
responsibly?
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18. Objectives
 Compare the differences between
renewable energy (solar, wind,
biomass, hydro) and non-renewable
energy (coal, oil and natural gas), and
their limitations
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19. Sources of energy
 Sources of energy can be broadly
classified into renewable or non-
renewable
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20. Non-Renewable Sources of Energy
 Non-renewable sources of energy are
limited and will run out one day. Most
non-renewable sources of energy are
obtained from fossil fuels.
 The three main types of fossil fuels are:
(a) crude oil (also known as petroleum),
(b) coal, and
(c) natural gas.
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21. Fossil fuels
 Fossil fuels are a form
of non-renewable
energy.
 While it takes millions
of years for fossil fuels
to form, it takes only a
short time to burn
them.
 There will come a day
when fossil fuels run
out.
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diesel and petrol are
used as fuels for motor
vehicles

22. Problems with using fossil
fuels
 Burning of fossil fuels
releases carbon dioxide
into the air which is a
greenhouse gas that
causes global warming
and climate change.
 Extraction of fossil fuels
can ruin landscapes.
 Mining of fossil fuels can
cause death and injury
to workers.
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freshly mined coal

23. Natural gas
 Natural gas is made up of mainly methane gas.
 It is used in power stations in Singapore to
generate electricity and also for cooking at home.
 There are also motor vehicles which are powered
by compressed natural gas (CNG).
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car running on Compressed
Natural Gas (or CNG) fuel.

24. Natural gas
 Compared to other fossil fuels, natural gas
is considered a clean fuel.
 Natural gas can be transported over long
distances using pipelines and large
tanker ships as it can be compressed into a
liquid.
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natural gas is used for cooking

25. Renewable Sources of
Energy
 Renewable sources of energy come from natural
resources such as wind, sunlight, water and plants.
 Renewable sources of energy can be used again.
They help to reduce the use of fossil fuels.
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The “Supertrees” at Gardens by the Bay
are installed with solar panels

26. Renewable Sources of
Energy
 Most renewable
sources of energy
do not cause air
pollution or
release
greenhouse gases
into the air.
 Examples of
renewable sources
of energy are wind
energy, solar
energy, biomass
and hydropower.
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the Hoover Dam generates
hydroelectric power

27. Wind Energy
 Wind is moving air which
has kinetic energy.
 Wind turbines convert
the kinetic energy of the
wind into electricity.
 Once the wind turbines
are built, the energy
obtained is effectively
free.
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kinetic energy of wind can
be converted into electrical energy
by using wind turbines

28. Wind Energy
 Wind energy is clean and does
not produce greenhouse
gases.
 Wind energy will not run out.
 The amount of electricity that
can be produced depends on
the strength of the wind so
wind turbines are built only in
places with strong winds
most days of the year.
 The wind in Singapore is
usually gentle, so wind energy
is not used here.
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The wind farms in Palm Springs,
California , are built along hilly areas

29. Solar Energy
 Solar energy is
energy from the Sun.
 Solar panels convert
solar energy into
electricity.
 Solar energy is clean,
free and will not run
out.
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solar panel mounted on a street lamp

30. Solar Energy
 Solar energy is suitable for places with lots of
sunlight throughout the year. This makes it
suitable for Singapore which has an average
of 12 hours of sunlight per day throughout
the year.
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solar panels mounted on rooftops in Singapore

31. Hydropower
 Hydropower refers to the energy obtained from flowing water.
 A dam is built to block a river. The water behind the dam is then
used to turn water turbines. The water turbines then turn
generators to produce electricity.
 As Singapore does not have big rivers with high water flow, we are
not able to use hydropower as a source of energy.
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a hydroelectric power plant

32. Hydropower
 Hydropower does not
produce any pollutants or
greenhouse gases.
 Once the dam is built,
electricity can be generated
as long as there is water flow.
 However, dams are very
expensive to build and can
cause large areas of land
upstream to be flooded.
 The ecosystem and habitats
of some animals can be
destroyed due to flooding.
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Three Gorges Dam in China

33. Comparing Renewable and Non-
Renewable Sources of Energy
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Activity Book Link
Activity 2.3 Sources of
Energy

34. Chapter 2 Discovering Energy
2.1 What are the different forms of
energy?
2.2 How can energy be converted from
one form to another?
2.3 What are the differences between
renewable and non-renewable
energy?
2.4 How can energy be used
responsibly?
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35. Objectives
 Appreciate that fossil fuels are
exhaustible and the need and ways to
reduce energy wastage
 Appreciate the importance of
conserving energy in our daily lives
because Singapore is dependent on
imported fossil fuels to meet its energy
needs.
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36. Why should we reduce energy wastage?
 We should reduce energy wastage as fossil
fuels cannot be replaced and burning
fossil fuels causes pollution problems.
 Singapore depends heavily on imported
fuels such as oil and natural gas from other
countries for our power stations and
vehicles to use.
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how can we conserve the use of electricity at home?

37. Using energy responsibly
 It is urgent and important for us
to use energy responsibly
and to encourage the use of
renewable sources of energy.
 Our government is also
encouraging the use of
energy-saving technology
and providing money to
research on clean energy.
 An example is the Carbon
Emissions-based Vehicle
Scheme (CEVS) where buyers
of cars with low carbon
emission will enjoy rebates
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hybrid car with low carbon emission

38. How can we conserve
energy?
 We can do our part to
conserve the use of
energy by:
(a) using only the
amount of energy
needed;
(b) developing the habit
of saving energy;
(c) taking public
transport;
(d) sharing this
message of conserving
energy with our family
and friends. © Copyright Star Publishing Pte Ltd 38
Project Carbon Zero is an energy-
saving competition project organised
by NEA and SEC for school students to
motivate them to reduce energy
wastage at home

39. Picture references
 Wind turbines
 http://www.doorsofperception.com/infr
astructure-design/could-green-energy-
kill-the-desert-2/
 Solar panels on rooftops
 http://oliveventures.com.sg/act/2012/1
1/14/solar-panel-leasing-in-singapore-
yes-please/
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