lss module 1 chpt 2 investigating energy

MODULE 1:GADGETS WORK WONDERS (I)Chapter 2 Discovering Energy

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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?


ObjectivesRecognise and give examples of

different forms of energy in everyday life (potential energy, kinetic energy, light energy, heat energy, electrical energy and sound energy)


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


Different forms of energy

light energy

kinetic energy

What is potential energy?Potential energy is stored energy.



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 astapler has elastic potential

energy

What is kinetic energy? Kinetic energy is the energy that moving objects

have.


moving objects have kinetic energy

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.


light helps plants to make food and the table lamp provides light for

reading.

What is heat energy?Heat energy keeps us warm in a cold

environmentand helps us cook our food.


Heat is needed to toast bread and for keeping warm beside a fireplace

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.


Electric hob (converts electrical

energy to heat energy)

Light bulb(converts electrical

energy to light energy)

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.


Activity Book LinkActivity 2.1Discovering Energy

hand bell (convertskinetic energy to

sound energy)

electronic alarm clock (converts electrical energy

to sound energy)

ObjectivesInvestigate energy conversion

from one form to another


Law of Conservation of EnergyEnergy cannot be created or destroyed.

It can only be converted from one form to another.


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

Useful energy conversions


using batteries as a source of electricity converts chemical

potential energy toelectrical energy

fossil fuels contain chemical energy which can be

converted toelectrical energy

audio-visualequipment converts electrical energy to

sound and light energy

Harmful energy conversions


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

causehearing loss as

kinetic energy is converted to sound

energy

Activity Book LinkActivity 2.2Steam Engine Model

ObjectivesCompare the differences between

renewable energy (solar, wind, biomass, hydro) and non-renewable energy (coal, oil and natural gas), and their limitations


Sources of energy Sources of energy can be broadly

classified into renewable or non-renewable


Non-Renewable Sources of EnergyNon-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.


Fossil fuelsFossil 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.


diesel and petrol are used as fuels for motor vehicles

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.


freshly mined coal

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).


car running on Compressed Natural Gas (or CNG) fuel.

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.


natural gas is used for cooking

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.


The “Supertrees” at Gardens by the Bay are installed with solar

panels

Renewable Sources of EnergyMost 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.


the Hoover Dam generates hydroelectric power

Wind EnergyWind 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.


kinetic energy of wind canbe converted into electrical

energyby using wind turbines

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.


The wind farms in Palm Springs, California , are built along hilly

areas

Solar EnergySolar energy is

energy from the Sun.

Solar panels convert solar energy into electricity.

Solar energy is clean, free and will not run out.


solar panel mounted on a street lamp

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.


solar panels mounted on rooftops in Singapore

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.


a hydroelectric power plant

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.


Three Gorges Dam in China

Comparing Renewable and Non-Renewable Sources of Energy


Activity Book LinkActivity 2.3 Sources of Energy

ObjectivesAppreciate 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.


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.


how can we conserve the use of electricity at home?

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


hybrid car with low carbon emission

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.


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

Picture referencesWind turbineshttp://www.doorsofperception.co

m/infrastructure-design/could-green-energy-kill-the-desert-2/

Solar panels on rooftopshttp://oliveventures.com.sg/act/2

012/11/14/solar-panel-leasing-in-singapore-yes-please/


http://www.doorsofperception.com/infrastructure-design/could-green-energy-kill-the-desert-2/



http://oliveventures.com.sg/act/2012/11/14/solar-panel-leasing-in-singapore-yes-please/



lss module 1 chpt 2 investigating energy

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