<< Chapter < Page Chapter >> Page >

Gebruik ‘n aardbol of ‘n kaart in jou atlas en maak seker dat jy verstaan wat elkeen van hierdie feite beteken.

  • Die Greenwich-meridiaan (0°-lengtelyn) vorm ‘n halfsirkel op die aardbol. As dit agterom die aardbol verleng word, vorm dit nog ‘n halfsirkel. Hierdie agterste halfsirkel word die antipode van die 0°-lengtelyn genoem en word 180° genommer. ‘n Lengtelyn en sy antipode vorm altyd ‘n volle sirkel. Vanaf die 0° lengtelyn kan daar dus 180° Wes en 180° Oos beweeg word.

So het elke lengtelyn ‘n antipode en as die twee lyne se graadnommers bymekaar getel word, gee dit altyd 180° as antwoord. ( bv. 0° O + 180° W = 180°)

Die Greenwich-meridiaan word as verwysing gebruik wanneer ‘n plek se tyd bepaal word.

Daar ontstaan egter nou ‘n probleem: As ons van die 0°-lengtelyn ooswaarts beweeg en van die 0°-lengtelyn weswaarts beweeg, bereik ons van albei kante die 180° lengtelyn. Nou gaan ons tye darem baie verskil!

  • Om die probleem op te los is die Internasionale Datumlyn (IDL) ontwikkel.

Dit volg die 180°-lengtelyn, maar sny nêrens oor land nie.

Die datum oos van die IDL is een dag vroeër; wes van die IDL is een dag later.

Van oos na wes verloor ‘n mens ‘n dag as jy oor die IDL beweeg.

Van wes na oos wen ‘n mens ‘n dag as jy oor die IDL beweeg.

Byvoorbeeld:

180° W 180° O
weswaarts ooswaarts
Beginpunt
verloor - + wen
Sondag Maandag Maandag
00 : 00 12 : 00 24 : 00
  • ‘n Plek se lengteligging is ook ‘n aanduiding van tyd :

Die aarde draai van wes na oos om sy eie denkbeeldige as. Die son kom dus vroeër op by plekke verder na die ooste.

Die son kom in Durban (31° O) ongeveer 50 minute vroeër as in Kaapstad (18½° O) op. In Suid-Afrika is so ‘n verskil nie ‘n probleem nie, want ons gebruik net een tydsone (30° O). In ‘n land soos die VSA is dit wel ‘n probleem. Die son kom in New York (74° W) ongeveer drie uur vroeër op as in San Francisco (122½° W). In die VSA is dit dus nodig dat daar verskillende tydsones moet wees.

  • Julle het seker al opgemerk dat as rugbywedstryde in Australië of Nieu-Seeland gespeel word en ons volg dit hier op TV, dit hier nog in die oggend is. Dit is so omdat daardie lande baie ver oos van Suid-Afrika lê en die son dus daar “vroeër” opkom.
  • Om die verskil in tyd te bereken, is nie so moeilik nie. Dit het alles te doen met die draaiing van die aarde om sy eie as.
  • Hoe lank neem dit vir die aarde om om sy eie as te draai?Dit duur 24 uur.
  • Deur hoeveel grade draai die aarde in hierdie 24 uur? Die aarde draai deur 360 ° .
  • Deel ons nou die 360° deur die 24 uur, blyk dit dat die aarde elke uur deur ‘n hoek van 15° draai. As twee plekke 15 lengtegrade uitmekaar lê, sal die son presies een uur vroeër by die plek opkom wat die verste oos lê.

Assessering

Leeruitkomstes(LUs)
LU 1
AARDRYKSKUNDIGE ONDERSOEKDie leerder is in staat om ondersoekvaardighede te gebruik om aardrykskundige en omgewingsbegrippe en -prosesse te ondersoek.
Assesseringstandaarde(ASe)
Dit is duidelik wanneer die leerder:
1.1 inligtingsbronne , insluitend eenvoudige statistiek, identifiseer om die vraag oor ‘n maatskaplike of omgewingsvraaagstuk of –probleem te help beantwoord;
  • relevante inligting vir spesifieke doeleindes uit bronne kies en dit opteken;
  • breedte- en lengteligging gebruik om relevante plekke op kaarte te vind;
  • inligting gebruik om oplossings vir probleme voor te stel;
1.5 verslag doen oor ondersoeke deur bespreking, debat, gestruktureerde skryfwerk, grafieke, tabelle, kaarte en diagramme.

Questions & Answers

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
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
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
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Aardrykskunde graad 6. OpenStax CNX. Sep 07, 2009 Download for free at http://cnx.org/content/col10999/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Aardrykskunde graad 6' conversation and receive update notifications?

Ask