<< Chapter < Page Chapter >> Page >

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

show that the set of all natural number form semi group under the composition of addition
Nikhil Reply
explain and give four Example hyperbolic function
Lukman Reply
_3_2_1
felecia
⅗ ⅔½
felecia
_½+⅔-¾
felecia
The denominator of a certain fraction is 9 more than the numerator. If 6 is added to both terms of the fraction, the value of the fraction becomes 2/3. Find the original fraction. 2. The sum of the least and greatest of 3 consecutive integers is 60. What are the valu
SABAL Reply
1. x + 6 2 -------------- = _ x + 9 + 6 3 x + 6 3 ----------- x -- (cross multiply) x + 15 2 3(x + 6) = 2(x + 15) 3x + 18 = 2x + 30 (-2x from both) x + 18 = 30 (-18 from both) x = 12 Test: 12 + 6 18 2 -------------- = --- = --- 12 + 9 + 6 27 3
Pawel
2. (x) + (x + 2) = 60 2x + 2 = 60 2x = 58 x = 29 29, 30, & 31
Pawel
ok
Ifeanyi
on number 2 question How did you got 2x +2
Ifeanyi
combine like terms. x + x + 2 is same as 2x + 2
Pawel
x*x=2
felecia
2+2x=
felecia
Mark and Don are planning to sell each of their marble collections at a garage sale. If Don has 1 more than 3 times the number of marbles Mark has, how many does each boy have to sell if the total number of marbles is 113?
mariel Reply
Mark = x,. Don = 3x + 1 x + 3x + 1 = 113 4x = 112, x = 28 Mark = 28, Don = 85, 28 + 85 = 113
Pawel
how do I set up the problem?
Harshika Reply
what is a solution set?
Harshika
find the subring of gaussian integers?
Rofiqul
hello, I am happy to help!
Shirley Reply
please can go further on polynomials quadratic
Abdullahi
hi mam
Mark
I need quadratic equation link to Alpa Beta
Abdullahi Reply
find the value of 2x=32
Felix Reply
divide by 2 on each side of the equal sign to solve for x
corri
X=16
Michael
Want to review on complex number 1.What are complex number 2.How to solve complex number problems.
Beyan
yes i wantt to review
Mark
use the y -intercept and slope to sketch the graph of the equation y=6x
Only Reply
how do we prove the quadratic formular
Seidu Reply
please help me prove quadratic formula
Darius
hello, if you have a question about Algebra 2. I may be able to help. I am an Algebra 2 Teacher
Shirley Reply
thank you help me with how to prove the quadratic equation
Seidu
may God blessed u for that. Please I want u to help me in sets.
Opoku
what is math number
Tric Reply
4
Trista
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
can you teacch how to solve that🙏
Mark
Solve for the first variable in one of the equations, then substitute the result into the other equation. Point For: (6111,4111,−411)(6111,4111,-411) Equation Form: x=6111,y=4111,z=−411x=6111,y=4111,z=-411
Brenna
(61/11,41/11,−4/11)
Brenna
x=61/11 y=41/11 z=−4/11 x=61/11 y=41/11 z=-4/11
Brenna
Need help solving this problem (2/7)^-2
Simone Reply
x+2y-z=7
Sidiki
what is the coefficient of -4×
Mehri Reply
-1
Shedrak
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Kimberly Reply
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
August Reply
What is the expressiin for seven less than four times the number of nickels
Leonardo Reply
How do i figure this problem out.
how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
Shanjida
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
s.
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play




Source:  OpenStax, Natuurwetenskappe graad 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11078/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Natuurwetenskappe graad 7' conversation and receive update notifications?

Ask