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Grade 8


Module 5

Beams, pillars, struts, crossbars and anchoring lines

Activity 1

Beams, pillars, supports/struts, crossbars and anchoring lines:

  • The above are important parts of structures. They are used in buildings, bridges and other objects. The pipes forming the framework of your bicycle, for instance, belong to the category of beams.
  • The main function of beams is to bear a load. If the load is too heavy, the beams will bend. In the past, tree trunks were used to provide solid beams, but the cost and weight of these have necessitated the development of different forms of structures, made from a variety of materials, used as beams.

  • Pillars and lampposts are beams that are used vertically. Pillars are useful in buildings for supporting overhanging verandas. If the pillars do not have the capacity to bear the load, the building will collapse. We now and again read about buildings, e.g. shopping centres that collapse.
  • Brackets of some or other type are sometimes used to mount TV sets against walls. It will be clear to you that the TV set causes stress to the platform on which it rests, which actually can be classed as a beam. Being supported at one end only, such a beam is called a crossbeam. To keep the crossbeam in position, a strut is used as support.
  • Similar struts are used in tents and for power lines. In such cases, the struts may be cables and ropes.

  • This sketch shows how a learner reinforced his bridge (a beam) made of drinking straws, by means of a strut and string.

Assignment 1

  • Examine the following illustrations and describe the ways in which technology was used to solve problems occurring in different cultures.

Assignment 2

  • Refer to the following and describe the impact that technological development with regard to structures has had on the lifestyle of people.
  • Skyscrapers
  • Aeroplanes
  • Roof trusses
  • Railway lines and trains
  • Bridges
LO 3.2


LO 3
TECHNOLOGY, SOCIETY AND THE ENVIRONMENT The learner will be able to demonstrate an understanding of the interrelationships between science, technology and the environment.
This is demonstrated when the learner:
indigenous Technology and Culture:3.1 compares how different cultures have solved similar problems and relates the differences to the culture and values of their societies;
impact of Technology:3.2 expresses and details opinions about the positive and negative impacts of products of Technology on the quality of people’s lives and the environment in which they live.



Allow learners to discuss beams, pillars, struts, crossbeams and anchor lines and to list examples. Let them explain where the stresses are exerted and what the application of a specific structure is, why it is suitable for the application and how it could be improved. In the case of a crossbar, the stress, for instance, is exerted below; a pillar bears vertical stress that is equally strong all over.

Assignment 1

  • It is important to use correct terminology when discussing examples:
  • Bow and arrow :Problem: It was necessary to hunt to get food. Animals could not be caught by hand. It became necessary to design a weapon.The bow and arrow as a structure: The string is used to exert the force of stress on the bow. The bending of the bow makes it possible to transfer this force to the arrow as the force of compression. The arrow, as a beam, causes the force to work in the direction of the arrow point to penetrate the prey.
  • CrossbowLike the bow and arrow, but more accurate and more powerful.
  • Shield and spearThe spear serves as a beam, which means that the force is exerted in the direction of the point, which can therefore penetrate the prey. The shield forms a shell structure, with the skin as shell and the wood as a frame.
  • SwordThe blade works as a beam.
  • Ordinary hutA shell structure, with the woodwork as frame and the grass as shell.
  • Rondavel and thatch-roofed housesLike ordinary huts, but with the clay forming part of the shell.

Assignment 2

  • Skyscrapers : larger numbers of people are able to inhabit a specific space. This facilitates urbanisation and makes demands on urban transport, sewerage, electricity supply, removal of storm water: problems that had to be solved by means of technology and have created job opportunities, which lead to further urbanisation.
  • Aeroplanes : great distances can be covered in brief periods of time, which means that both people and goods can be transported quickly. This, however, has implications with regard to pollution and the utilisation of natural resources. It also increases the tempo of living.
  • Roof trusses : For people who live in inhospitable climatic regions, roof trusses prevent roofs from collapsing when there are heavy snowfalls and hail.
  • Railway lines and trains : As with aeroplanes, but trains have also enabled people to spread civilisation across the globe.
  • Bridges : as with aeroplanes and trains.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
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?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
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.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Technology grade 8. OpenStax CNX. Sep 13, 2009 Download for free at http://cnx.org/content/col11052/1.1
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