<< Chapter < Page Chapter >> Page >
To identify the sources of energy of common items

Natural sciences

Energy transfers and forces

Educator section


3. Flashlight of camera - battery

4. Paraffin heater - paraffin

5. Gas heater - gas

6. Hair drier - electricity

7. Windmill - wind etc.

Leaner Section


Activity 3: to identify the sources of energy of common items [lo 1.2]

Think of some of the items in your homes and of any other things that are able to perform some kind of movement. Then do the following activity with a partner by trying to complete the list:

car petrol/diesel
train electricity/coal
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________

3. Fuels

The plants and animals that existed millions of years ago absorbed the sun’s energy while they were growing. They were buried under the layers of rock that eventually formed over them. Then their remains were gradually changed into oil, coal and various gases by means of chemical reactions. These fuels are known as fossil fuels . Oil, coal and gases are non-renewable , i.e. they cannot be replaced. In addition, they have to be mined from underground reserves and burning them damages our environment and our health. One non-renewable energy source that is not derived from fossils, is nuclear power. Some metals, like uranium, release enormous amounts of energy when they undergo nuclear fission. Nuclear power is utilised for manufacturing electricity, e.g. at the nuclear power station at Koeberg where electricity is generated for the use of the inhabitants of Cape Town. A small amount of nuclear power produces large amounts of nuclear fuel and causes very little environmental pollution. At present also large amounts of nuclear fuel are available. Nuclear power stations have to be built near the sea, because they need great amounts of water for cooling. This means that the energy sometimes has to be transported over long distances. Radioactive radiation can lead to health risks and it takes hundreds of years for radioactive nuclear waste to lose its radioactivity. Such waste therefore has to be buried underground in special containers for many years. Nuclear power, however, does not cause acid rain or contribute to the greenhouse effect, which is what fossil fuels do.

Because these non-renewable fuels are not expected to be available in the future, we need to conserve energy and begin to make use of alternative energy sources like the sun, water, wind, waves, tides and bio-gases for power. Great progress has already been made with the development of these forms of energy.


Learning Outcome 1: The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard 1.2: We know this when the learner conducts investigations and collects data: organises and uses apparatus/equipment or sources to gain and record information.

Questions & Answers

how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Berger describes sociologists as concerned with
Mueller Reply
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Natural sciences grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11077/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Natural sciences grade 7' conversation and receive update notifications?