<< 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

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
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
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
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
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
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
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
Prasenjit
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Berger describes sociologists as concerned with
Mueller Reply
Got questions? Join the online conversation and get instant answers!
QuizOver.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