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Natuurwetenskappe

Energie-oordrag en kragte

Opvoeders afdeling

Memorandum

3. Flitslig van kamera - battery

4. Paraffienverwarmer paraffien

5. Gasverwarmer - gas

6. Haardroër - elektrisiteit

7. Windmeul - wind, ens.

Leerder afdeling

Inhoud

Aktiwiteit: om die energiebronne van alledaagse items te identifiseer [lu 1.2]

Dink aan items in julle huise en aan dinge wat beweeg, en doen dan die volgende saam met ‘n maat. Probeer om die lys te voltooi:

ITEM BRON VAN ENERGIE
motor petrol / diesel
trein elektrisiteit / steenkool
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________

3. Brandstowwe

Die plante en diere wat miljoene jare gelede gelewe het, het die son se energie geabsorbeer terwyl hulle gegroei het. Hulle is begrawe onder rotslae wat mettertyd oor hulle gevorm het. Hulle oorblyfsels is geleidelik deur verskillende chemiese reaksies in olie, steenkool en gasse verander. Ons noem hierdie brandstowwe fossielbrandstowwe . Olie, steenkool en gasse is nie-hernubaar , d.w.s. hulle kan nie vervang word nie. Daarbenewens moet hulle uit ondergrondse reserwes gemyn word en hul verbranding doen skade aan ons omgewing en ons gesondheid. Een nie-hernubare energiebron wat nie ‘n fossielbrandstof is nie, is kernkrag . Sekere metale soos uraan ondergaan ‘n proses wat ons kernsplitsing noem en stel dan groot hoeveelhede energie vry. Kernkrag word bv. by die kernkragstasie by Koeberg gebruik om elektrisiteit op te wek wat deur die inwoners van Kaapstad gebruik word. ‘n Klein hoeveelheid kernkrag lewer groot hoeveelhede kernbrandstof en veroorsaak baie min omgewingsbesoedeling. Daar is ook tans groot hoeveelhede kernbrandstof beskikbaar. Kernkragsentrales moet naby die kus gebou word as gevolg van die behoefte aan waterverkoeling. Dit bring mee dat die energie soms oor lang afstande vervoer moet word. Radioaktiewe bestraling kan lei tot gesondheidsgevare en dit neem honderde jare voordat radioaktiewe kernafvalprodukte nie meer radioaktief is nie en moet dus vir baie jare in spesiale houers ondergronds geberg word. Kernkrag veroorsaak egter nie suurreën of die kweekhuiseffek soos fossielbrandstowwe nie.

Omdat hierdie nie-hernubare brandstowwe nie meer vir baie lank beskikbaar gaan wees nie, moet ons energie bespaar en van alternatiewe energiebronne soos die son, water, wind, golwe, getye en biogasse begin gebruik maak vir ons krag. Groot vordering is reeds op hierdie gebied gemaak.

Assessering

Leeruitkomste 1: Die leerder is in staat om met selfvertroue op weetgierigheid oor natuurlike verskynsels te reageer, en om binne die konteks van wetenskap, tegnologie en die omgewing verbande te ondersoek en probleme op te los.

Assesseringstandaard 1.2: Dit is duidelik wanneer die leerder ondersoeke uitvoer en data versamel: organiseer en gebruik toerusting of bronne om inligting in te versamel en aan te teken

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
Maciej
Do somebody tell me a best nano engineering book for beginners?
s. Reply
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Devang Reply
are you nano engineer ?
s.
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.
Virgil
is Bucky paper clear?
CYNTHIA
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.
Harper
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s.
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SUYASH Reply
for screen printed electrodes ?
SUYASH
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s. Reply
of graphene you mean?
Ebrahim
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s.
Graphene has a hexagonal structure
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Cied
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abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
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Porter
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Yasmin
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Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
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
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
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
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
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
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
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Damian
silver nanoparticles could handle the job?
Damian
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Azam
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Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
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Source:  OpenStax, Natuurwetenskappe graad 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11078/1.1
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