OpenStax-CNX module: m20193
1
To be able to describe static
electricity and lightning as
sources of energy
∗
Siyavula Uploaders
This work is produced by OpenStax-CNX and licensed under the
†
Creative Commons Attribution License 3.0
1 NATURAL SCIENCES
2 Planet earth and the universe
3 Sources of energy and energy systems
4
5 EDUCATOR SECTION
6 Memorandum
Static:
• Shop trolleys have little chains that trail on the ground. Charges ow into the ground.
• Happens when something is rubbed and there is resistance, e.g. hands on a handle, clothes on a seat,
etc.
Lightning:
Any examples, e.g.
•
•
•
•
•
Don't stand in front of open doors and windows.
Wear shoes with rubber soles.
Stay away from wire fences.
Lie at. Never stand upright or on an object.
Install lightning conductors.
Don't use the telephone when there is lightning.
∗ Version
1.1: Mar 12, 2009 2:06 am -0500
† http://creativecommons.org/licenses/by/3.0/
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OpenStax-CNX module: m20193
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8 LEANER SECTION
9 Content
• The natural sources of energy that we have examined, namely sun, wind and water, only partially
meet the need for energy. Little attention has been paid to the development of these sources because
it is dicult to capture, store and control these sources. The following are the main resources used to
supply the human need for energy.
Figure 1
Nuclear power is the newest and most dangerous fuel that is available.
We will now examine the sources of electrical energy, the following in particular:
static electricity and lightning
cells
batteries
dynamos
coal-driven power stations
nuclear power
You have already become acquainted with some of these sources in Grade 5. This year we are going to
deal with them in more detail. We are also going to help you to understand what energy systems are and
how some of the sources can be described as systems.
Meanwhile, remember the following denition of a system:
A system consists of two or more parts that work together or inuence one another.
10 ACTIVITY: To be able to describe static electricity and lightning as sources
of energy [LO 2.3]
• STATIC ELECTRICITY
We have learnt that static electricity is present in the air around us at all times. Static electricity is not very
powerful, but we can make it more powerful by means of friction.
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OpenStax-CNX module: m20193
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Figure 2
Static electricity can also cause an unpleasant electrical shock. Metal shopping trolleys used in shops are
made in a way that allows the electricity that builds up to be conducted away.
Figure 3
• Discuss this method of conduction in your group and draw a picture of shopping trolley.
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• How does static electricity originate?
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OpenStax-CNX module: m20193
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• LIGHTNING
You have learnt that all materials are composed of small particles. Such particles are sometimes charged with
electricity. They can be positively or negatively charged. Electricity is generated when negatively charged
particles move from one place to another. Sometimes the ow of electricity is observed as a spark. Lightning
is a great deal of electricity that is observed as a spark in the air. One could say that lightning results from
large numbers of negatively charged particles moving from one cloud to another.
• Write down some safety measures that can be applied during a thunderstorm.
1.___________________________________________________________________
2. ___________________________________________________________________
3. ___________________________________________________________________
4. ___________________________________________________________________
11 Assessment
The learner will know and be able to interpret and apply scientic, technological
and environmental knowledge.
Assessment Standard 2.3: We know this when the learner interprets information
Learning Outcome 2:
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