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Natuurwetenskappe

Energie-oordrag en kragte

Opvoeders afdeling

Memorandum

Waarnemings:

(i) Die rook trek opwaarts.

(ii) Die rook trek opwaarts.

(iii) Die rook trek opwaarts.

Afleiding:

Warm lug styg op.

Gedurende die dag word die land vinniger warm as die see. Die warm lug bo die land styg op. Koeler lug bo die see vloei na die land om die plek van die warm lug in te neem. So ontstaan seewinde.

Snags koel die land vinniger as die see af. Die warm lug bo die see styg dus. Koeler lug bo die land vloei na die see om die plek van die warm lug in te neem. So ontstaan landwinde.

Leerder afdeling

Inhoud

Aktiwiteit: om stroming as natuurverskynsel te verklaar [lu 1.1, lu 1.2, lu 1.3]

(b) Stroming

Stroming is die belangrikste manier waarop warmte deur ‘n vloeistof beweeg. Water is ‘n swak geleier van warmte, maar tog kry ‘n ketel dit reg om water vinnig te laat kook. Dit is omdat vloeistowwe kan beweeg. Wanneer die water warm word, styg dit. Koue water daal dan af om die plek in te neem van die warmer vloeistof wat opgestyg het. In die meegaande skets sal jy sien dat hierdie sirkelbeweging, ‘n konveksiestroom, die warmte deur die vloeistof versprei totdat al die water later so warm is dat dit kook (100º C – kookpunt van water by seespieël).

Alhoewel lug ook ‘n swak geleier van warmte is, kry ons dit reg om ‘n vertrek met behulp van ‘n verwarmer te verhit. Neem ‘n brandende kers. Hou die rigting van die rook dop terwyl jy

(i) die kers regop hou __________________________________________________

(ii) die kers skuins hou _________________________________________________

(iii) die kers onderstebo hou _____________________________________________

Noteer jou waarnemings. Watter afleiding kan jy maak?

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Omdat warm lug styg, vind daar ook stroming in die natuur plaas. Het jy al gewonder waar wind vandaan kom? Warm lug styg en koue lug neem die plek daarvan in.

Gebruik die beginsel van konveksiestrome in lug om te onderskei tussen land- en seewind. Jy kan ook ‘n skets maak om jou gegewens te verduidelik.

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(c) Straling

Om energie oor te dra deur geleiding of stroming is ‘n vaste stof, ‘n vloeistof of ‘n gas nodig. Daar moet een of ander stof wees om die warmte-energie oor te dra. Deur straling kan energie deur ‘n leë ruimte oorgedra word. Warmte-energie van die son beweeg deur die ruimte en deur die aarde se atmosfeer en wanneer dit ‘n voorwerp tref, word die voorwerp verhit.

As mens op ‘n baie warm dag op ‘n pad ry waar jy ver voor jou uit kan sien, lyk dit asof daar water op die teerpad lê. Die warm teerpad straal hitte uit. ‘n Voorbeeld van straling in die alledaagse lewe is wanneer ons in die winter ‘n elektriese verwarmer gebruik om ‘n vertrek te verwarm.

6. Omsetting van energie

Watter soort energie gebruik die seun om die tennisbal te slaan?

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Watter soort energie het die bewegende tennisbal?

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Jy het waarskynlik nou die idee gekry dat energie kan verander. Wanneer energie van een soort verander in ‘n ander soort, vind energie-omsetting plaas.

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 1.1: Dit is duidelik wanneer die leerder ondersoeke beplan: beplan eenvoudige toetse en vergelykings en dink na oor hoe om dit billik te maak;

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

Assesseringstandaard 1.3: Dit is duidelik wanneer die leerder data evalueer en bevindings kommunikeer: veralgemeen ten opsigte van ‘n relevante aspek en beskryf hoe die data die veralgemening steun

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
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..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
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.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
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
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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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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