<< Chapter < Page Chapter >> Page >

Natural sciences

Energy transfers and forces

Educator section

Memorandum

(i) Refrigerator; kettle; toaster

(ii) Convection heater; fan heater; iron

(iii) Refrigerator; kettle; vacuum cleaner or toaster

(iv) Food mixer; convection heater; fan heater; filter

E.g. heaters can be replaced by isolating ceilings, carpets on cement floors, properly sealed panes, etc.

Leaner section

Content

Activity 10: to compare the energy consumption of a variety of electrical appliances [lo 3.2]

a. Study the following and answer the questions that follow:

With one unit of electricity ______________________________________________

The above illustrates the working costs of some household appliances with reference to their consumption per unit of electricity.

(i) Which three appliances use the least energy?

_____________________________________________________________________

(ii) Which three appliances are the most expensive to operate?

_____________________________________________________________________

(iii) Which appliances are used most frequently in households?

_____________________________________________________________________

(iv) Which appliances would you regard as unnecessary and replaceable with other appliances that do not use as much fuel, or as altogether dispensable.

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

(b) Many people in South Africa do not have access to electricity and have to use fuel wood, paraffin or gas as fuels to cook their food and warm their houses. Fuels, especially wood, are becoming scarcer and people often have to walk great distances to collect what they need. These fuels also need to be used effectively to help with conservation.

Many of the people who depend on fuel wood use open fireplaces and much heat energy is transferred into the surrounding air. Often people also use gas stoves incorrectly and waste energy.

GROUP WORK

Each group is to select a means that is used for cooking by a majority of South Africans in rural areas, e.g. an open fire, a gas stove, etc. This must be represented practically by means of a model and a report must be written on its use. The report should cover the following questions:

Which fuel is used?

  • Is it easily obtainable?
  • Is a particular colour recommended for the pot? If so, what is the reason for it?
  • Which measures can be taken to limit heat energy being lost into the air around the pot?
  • What is the cost of the fuel?

Educator’s Assessment:

Criteria 1 2 3 4
Assignment: Correctly executed; complete; relevant; handed in on time
Model: Effective; fuel indicated; creative representation
Report: All questions addressed; reporting neat; good language use
Co-operation within group: Effective; differences resolved; all learners involved
DOMINANT CODE

Assessment

Learning Outcome 3: The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.

Assessment Standard 3.2: We know this when the learner understands sustainable use of the earth’s resources: analyses information related to renewable and non-renewable sources.

Questions & Answers

are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
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
has a lot of application modern world
Kamaluddeen
yes
narayan
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
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 Download on the App Store Now




Source:  OpenStax, Natural sciences grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11077/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Natural sciences grade 7' conversation and receive update notifications?

Ask