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Natuurwetenskappe

Graad 8

Energie: elektrisiteit, energie, warmte en lig

Module 10

Hitte en temperatuur

Hitte is ‘n soort energie – alle atome / molekules vibreer. Ons ervaar dit as hitte.

Temperatuur is die meting van hoe vinnig die molekules beweeg.

Hoe meet jy temperatuur?

‘n Termometer word gebruik. Dit bestaan uit ‘n glasbuis met ‘n vloeistof, bv. kwik, daarin wat uitsit tydens verhitting.

Wat is absolute zero ?

Dit is die koudste moontlike temperatuur waarby molekules of atome glad nie meer kan beweeg nie. Dit gebeur by –273,15 ºC of by 0 op die Kelvin-skaal. Dit is in ‘n Finse laboratorium gemeet.

Vind uit: Wat is die Kelvin-skaal ?

Jy weet seker dat ‘n mens temperatuur op ‘n Celsius-skaal of Fahrenheit-skaal kan meet. Sommige toestelle meet in Fahrenheit, bv. oonde, terwyl ander weer Celsius gebruik.

Hoe skakel jy Fahrenheit om na Celsius?

(Grade F – 32) ÷ 9 x 5 = C

Om Celsius na Fahrenheit om te skakel:

F = C ÷ 5 x 9 + 32

Aktiwiteit 1:

Om temperatuuromskakeling te verstaan

[lu 2.4]

Opdrag 1:

Het jy geweet?

1. Die hoogste temperatuur wat ooit op aarde gemeet is, was 720 miljoen°F, tydens ‘n kernfusie-eksperiment in Amerika.

Hoeveel is dit in ºC?

2. Die hoogste lugtemperatuur gemeet, was 58ºC in Libië.

Hoeveel ºF is dit?

3. Die laagste lugtemperatuur gemeet was in Antarktika en dit was –190 ºF.

Hoeveel ºC is dit?

Probeer gerus: www. convert-me.com

Hitteoordrag

Aktiwiteit 2:

Om hitte-oordragterme en -begrippe vas te stel

[lu 2.1, 2.3, 2.4]

Opdrag 1:

Voltooi:

Daar is verskillende terme wat hitte-oordrag beskryf:

KONVEKSIE:

GELEIDING:

STRALING

Hitte en Water

Water het ‘n uitsonderlike hittehouvermoë.

Dit neem baie energie voordat ‘n massa water met 1 ºC styg of daal.

Daar is verskeie faktore betrokke:

  • Water is ‘n vloeistof.
  • Water is deurskynend en ligstrale kan tot 20 m diep penetreer.
  • Watermassa het golwe en strome en vertikale beweging wat hitte kan versprei.

As jy die hittehouvermoë van die land en die oseane vergelyk, sal jy besef dat dit baie verskil.

Warmtekapasiteit

Ons weet reeds dat warmte ‘n verandering in temperatuur veroorsaak en dat die eenheid van hierdie warmte in Joule gemeet word, aangesien dit ‘n soort energie is.

Spesifieke warmtekapasiteit is die hoeveelheid warmte wat oorgedra (benodig/vrygestel) word as die temperatuur van ‘n stof met 1 ºC of 1 K verander.

Water is die duurste om te verhit, omdat groot hoeveelhede warmte vereis word om die temperatuur slegs ‘n paar grade te laat styg. Water sal egter ook groot hoeveelhede warmte lewer, indien dit afkoel.

Die uitwerking hiervan is die duidelikste op oseane, wat groot watermassas is. Dit verhit baie stadig, maar hou dan lank die warmte.

Opdrag 2:

  1. Verduidelik hoekom kusdorpe so ‘n gematigde temperatuur het as jy dit vergelyk met binnelandse dorpe.

2. Koel tee die vinnigste af wanneer jy eers koue melk byvoeg en dit dan laat staan of wanneer jy dit eers laat staan en dan koue melk byvoeg? Verduidelik.

3. Hoekom is die water by die strand lekker warm op ‘n koue dag as dit op ‘n paar warm dae volg?

4. Watter faktore dra by tot water se besondere warmtekapasiteit?

Questions & Answers

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
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
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
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.
Bharti
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
Daniel
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
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
How can I make nanorobot?
Lily
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
NANO
how can I make nanorobot?
Lily
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
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.
Tarell
what is the actual application of fullerenes nowadays?
Damian
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.
Tarell
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Source:  OpenStax, Natuurwetenskappe graad 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11049/1.1
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