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Natural sciences

Energy transfers and forces

Educator section

Memorandum

(a) Petrol – motor-car

Gas – stove

Coal – steam locomotive

Wood – fire to provide heat

Crude oil – aeroplane fuel is derived from it

(b) Wind-propelled devices – wind farm

Engines that move by means of used cooking-oil

Solar heating for warmth

(c) Advantages and disadvantages of nuclear fuels and fossil fuels.

(i) Fossil fuels

Advantages Disadvantages
Quite readily available. Causes air pollution – emits smoke and harmful gases.
Can easily be converted to energy. Presents a fire hazard.
Relatively inexpensive. Mining defaces the environment.

(ii) Nuclear fuels

Advantages Disadvantages
A great deal is available. Health risks caused by radioactive eradiation.
Minimal pollution of the environment. Energy must be transported over long distances, seeing that power stations have to be built near the coast because of the water cooling systems that are used.
A small amount produces a great deal of energy. Radioactive waste must be stored safely for years until the radioactivity disappears.

Leaner Section

Content

Activity 4: to list fuels and their uses [lo 1.3]

(a) Name five common fuels and one use of each:

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(b) It is very important for people to find other sources of energy. Try to suggest ways in which people can use energy differently or make use of other sources, e.g. electric cars.

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(c) Name three advantages and three disadvantages of:

(i) Fossil fuels

ADVANTAGES DISADVANTAGES
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(ii) Nuclear fuels

ADVANTAGES DISADVANTAGES
1.___________________________________________________________ 1.___________________________________________________________
2.___________________________________________________________ 2.___________________________________________________________
3.___________________________________________________________ 3.___________________________________________________________

(d) Consider the sources of energy that we have been discussing and then draw up a list to show how you could conserve energy, e.g. by switching off the lights in the classroom when the sun is shining.

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4. forms of energy

The human body does not use fuel (food) in the form in which we take it. The food is broken down into simple substances that are conserved in the muscles, in the particular form that can be used by the muscles. There therefore is energy in the substances that are stored in the muscles. Energy that is stored in chemical substances like food and fuel is known as chemical energy. All fuels therefore contain chemical energy.

Chemical energy is released when some reaction occurs. If coal is burnt, for instance, it releases heat that can then be used to generate steam for a steam locomotive.

Heat energy is used every day. We need it to cook our food and to keep warm.

Heat energy boils the water in the locomotive’s kettle and this forms steam.The steam drives the locomotive.

The sun provides us with light, as do fuels and electricity. When electricity flows through the filament in a light bulb, the wire is heated and glows. It releases light energy , as well as a small amount of heat energy. Some worms, fireflies and fish also radiate light energy.

Kinetic energy results from movement. Moving water can turn a water wheel, while wind can drive a wind pump.

Energy that is stored in things and waiting to be released by some means or other is called potential energy. The spring of an air gun that is loaded has the ability to fire. We therefore say that the loaded spring has potential energy.

Assessment

Learning Outcome 1: The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard 1.3: We know this when the learner evaluates data and communicates findings: generalises in terms of relevant aspects and describes how the data support the generalisation.

Questions & Answers

how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
Shelly Reply
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu
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Source:  OpenStax, Natural sciences grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11077/1.1
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