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Natural sciences

Grade 4

Energy and change

Module 28

Making energy available to people


Energy from sunlight is stored in and around the earth in several ways. (In some instances temporarily, as when the earth is warmed by the sun, or for longer periods of time, for instance when it is fixed in food). The stored energy can be released later and be used.

Let us take a look at some of the means by which it may be released


Using wind as a source of energy to our advantage

[lo 1.1, 1.2, 1.3, 2.1]

See how many of the following idiomatic expressions that have developed around the idea of wind are known to you?

  • We got wind that you were coming (we were given a hint)
  • His talk was all wind (it was insubstantial)
  • Between wind and water (a vulnerable spot, as the part of a ship that is normally below water but is exposed when the ship rolls)
  • How the wind blows (what appears probable)
  • In the wind (about to happen)
  • Three sheets in the wind (intoxicated or drunk)
  • Sail close to the wind (come near the limits of danger)
  • Take the wind out of someone’s sails (destroy someone’s advantage)

What is wind?

Blow on your hand. What do you notice?

We cannot see the wind, but we can feel it when it blows against our faces or ruffles our hair.

Washing dries quickly if it is hung out in the wind.

Do you know the reason for this?

How does wind occur?

Complete the sentences to explain the illustration by supplying the missing words:

  1. By day the sun . It .

the land.

  1. Warm air .
  2. Cooler air moves from the to the

to take the place of the warm air.

  1. This is how originates.

Make a windmill

  • Use stiff paper. Cut it according to the instructions on the illustrations.
  • Will this windmill turn in a room where there is no wind?
  • What could you do to make it turn?
  • Discuss suggestions about how to increase the windmill’s turning speed with your friends and report your ideas to the class.

Folding a small paper glider:

  • Fold a sheet of A4 paper in half lengthways.
  • Unfold the sheet of paper and fold the two top corners to the central fold so that the top edges lie together.
  • Fold the new corners to the central fold, forming a sharp arrow point.
  • Fold back the arrow point to the point at which the other points meet.
  • Fold along the original lengthways fold again to “close” the structure.
  • Fold the bottom corners separately to form wings.
  • Fold back both wings along a line lying parallel to the central fold.
  • Hold below and throw gently, noting how far the glider glides!
  • You may experiment to see which folding pattern allows the glider to glide better. Demonstrate this to the class and motivate your explanation.

Ways in which wind is used to the benefit of people

People have always made use of the power of wind to achieve things.

People have used the wind to their advantage. Sailors use the power of the wind that blows against their sails to drive their ships.

Windmills have been used to grind wheat and wind pumps pump water from below the ground.

The wind blows against the sails of the mill or the vanes of the wind pump to turn them. This turning turns machinery inside the mill. Modern windmills are called turbines and are used to provide electricity.

Class project

Let’s build a kite! First name and describe the materials that we could use for this project. Then form groups to build kites.


LEARNING OUTCOME 1: SCIENTIFIC INVESTIGATIONSThe 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

We know this when the learner

1.1 plans investigations;

  • leads investigations and collects data;
  • evaluates data and provides feedback on observations.


The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

Assessment Standard

We know this when the learner

2.1 recalls significant information.


What is wind?

I feel air on my hand.

The wind shakes drops of water from the washing. The vapour from the washing disappears into the air.

Where does the wind come from?

Complete the sentences by using the missing words in order to explain the illustration:

1. shines, warm

2. rises

3. sea, land

4. wind

Make a windmill

Use a sheet of firm paper. Fold it according to the instructions on the illustrations.

Does a windmill turn in a room where there is no air current (wind)? No!

What can you do to make it turn? I can run while holding it in the air.

Questions & Answers

who was the first nanotechnologist
Lizzy Reply
technologist's thinker father is Richard Feynman but the literature first user scientist Nario Tagunichi.
Norio Taniguchi
I need help
anyone have book of Abdel Salam Hamdy Makhlouf book in pdf Fundamentals of Nanoparticles: Classifications, Synthesis
Naeem Reply
what happen with The nano material on The deep space.?
pedro Reply
It could change the whole space science.
the characteristics of nano materials can be studied by solving which equation?
sibaram Reply
plz answer fast
synthesis of nano materials by chemical reaction taking place in aqueous solvents under high temperature and pressure is call?
hydrothermal synthesis
how can chip be made from sand
Eke Reply
is this allso about nanoscale material
are nano particles real
Missy Reply
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
where is the latest information on a no technology how can I find it
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
has a lot of application modern world
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
STM - Scanning Tunneling Microscope.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 4. OpenStax CNX. Sep 18, 2009 Download for free at http://cnx.org/content/col11096/1.1
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