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Natural sciences

Grade 9

Energy: forces and machines

Module 21

Work and conversion of energy

Activity 1:

Describing the relationship between effort and energy with reference to a turbine

[LO 1.2, 2.1, 3.2]

Energy is necessary for any performance of work. This energy must be obtained from FUELS or from CONVERTED forms.

CONSTRUCTING A SIMPLE TURBINE

  • Use a tin lid, cut it into segments to form it into a fan and make a hole in the centre.
  • Nail the fan to a piece of wood.
  • Boil water in a kettle, until there is a strong draught of steam.
  • Hold the fan in position so that the jet of steam will be directed towards its centre.
  • QUESTIONS

1. What happened?

2. What kind of energy conversion occurred?

3. Describe the form of energy conversion that occurs with wind towers such as those that have recently been erected along the West Coast in the vicinity of Malmesbury.

4. What advantages do wind towers like these have for the environment?

  • Write a paragraph (60 words) about the value that the principle of the turbine has for people.
  • WORK is also measured in (give the name of the unit) .…………....................................

Activity 2

Discussing other machines that operate by means of conversion of energy

THE MICROSCOPE

  • As long ago as the early 17 th century, Robert Hook assumed that light rays have energy and that a wound-up spring has potential energy. He also constructed the first microscope and was the first person to use the universal lever, which is used in a wide range of instruments and cars.

SATELLITES

  • Satellites depend on solar panels to absorb light energy from the sun and supply electricity for all other electronic functions and for cameras and radio equipment. Energy is also stored in chemical form in rechargeable batteries.

WIND PUMPS

  • The blades of the rotary disk are turned by the wind to drive a pump that pumps underground water to a storage dam.

Assignment 3: GROUP DISCUSSION

  • Name at least three other machines that operate by means of energy conversion and explain the workings of each one.

WHEN IS A MACHINE MECHANICALLY INEFFECTIVE?

  • When a machine or appliance fails to provide an adequate quantity of the energy that it has been designed to provide we say that it is in affective.
  • The light bulb, for instance, releases (unwanted) heat, but was actually designed to provide light!
  • In this instance, fluorescent lighting is more effective and economical.
  • Are you able to list further examples?

Assessment

LO 2
Scientific KnowledgeThe learner will know and be able to interpret and apply scientific, technological and environmental knowledge.
This is displayed when the learner:
2.1 is able to recall meaningful information;
2.2 is able to arrange information according to categories;
2.3 is able to interpret information;
2.4 is able to apply knowledge.
LO 3
Science, Environment and the CommunityThe learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.
This is displayed when the learner:
3.1 is able to show appreciation of science as a human endeavour;
3.2 is able to recognise the value of sustainable utilisation of resources.

Memorandum

Activity 1

Questions:

1. The fan (‘turbine’) rotates

2. Chemical to steam to kinetic / mechanical

3. Kinetic to electrical to chemical

4. Natural resources (e.g. coal) are not used and pollution is avoided

Paragraph:

  • E.g. natural energy is converted to usable energy
  • Without consumption of resources
  • Without pollution
  • There are no waste products to be got rid of
  • Examples of utilising turbines: generation of electricity, previously also for driving mills

Effort is measured in Joule

Activity 2

  • Any power generator
  • Compressor
  • Vehicle engine
  • Sewing machine
  • Kitchen appliances
  • Etc.
  • Ineffective machines: any machine or system that releases energy in a non-usable form, e.g. a car that is driven with the hand break on (much energy is wasted in the attempt to overcome the force of friction – energy in the form of heat goes to waste).

Questions & Answers

Discuss the differences between taste and flavor, including how other sensory inputs contribute to our  perception of flavor.
John Reply
taste refers to your understanding of the flavor . while flavor one The other hand is refers to sort of just a blend things.
Faith
While taste primarily relies on our taste buds, flavor involves a complex interplay between taste and aroma
Kamara
which drugs can we use for ulcers
Ummi Reply
omeprazole
Kamara
what
Renee
what is this
Renee
is a drug
Kamara
of anti-ulcer
Kamara
Omeprazole Cimetidine / Tagament For the complicated once ulcer - kit
Patrick
what is the function of lymphatic system
Nency Reply
Not really sure
Eli
to drain extracellular fluid all over the body.
asegid
The lymphatic system plays several crucial roles in the human body, functioning as a key component of the immune system and contributing to the maintenance of fluid balance. Its main functions include: 1. Immune Response: The lymphatic system produces and transports lymphocytes, which are a type of
asegid
to transport fluids fats proteins and lymphocytes to the blood stream as lymph
Adama
what is anatomy
Oyindarmola Reply
Anatomy is the identification and description of the structures of living things
Kamara
what's the difference between anatomy and physiology
Oyerinde Reply
Anatomy is the study of the structure of the body, while physiology is the study of the function of the body. Anatomy looks at the body's organs and systems, while physiology looks at how those organs and systems work together to keep the body functioning.
AI-Robot
what is enzymes all about?
Mohammed Reply
Enzymes are proteins that help speed up chemical reactions in our bodies. Enzymes are essential for digestion, liver function and much more. Too much or too little of a certain enzyme can cause health problems
Kamara
yes
Prince
how does the stomach protect itself from the damaging effects of HCl
Wulku Reply
little girl okay how does the stomach protect itself from the damaging effect of HCL
Wulku
it is because of the enzyme that the stomach produce that help the stomach from the damaging effect of HCL
Kamara
function of digestive system
Ali Reply
function of digestive
Ali
the diagram of the lungs
Adaeze Reply
what is the normal body temperature
Diya Reply
37 degrees selcius
Xolo
37°c
Stephanie
please why 37 degree selcius normal temperature
Mark
36.5
Simon
37°c
Iyogho
the normal temperature is 37°c or 98.6 °Fahrenheit is important for maintaining the homeostasis in the body the body regular this temperature through the process called thermoregulation which involves brain skin muscle and other organ working together to maintain stable internal temperature
Stephanie
37A c
Wulku
what is anaemia
Diya Reply
anaemia is the decrease in RBC count hemoglobin count and PVC count
Eniola
what is the pH of the vagina
Diya Reply
how does Lysin attack pathogens
Diya
acid
Mary
I information on anatomy position and digestive system and there enzyme
Elisha Reply
anatomy of the female external genitalia
Muhammad Reply
Organ Systems Of The Human Body (Continued) Organ Systems Of The Human Body (Continued)
Theophilus Reply
what's lochia albra
Kizito
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Source:  OpenStax, Natural sciences grade 9. OpenStax CNX. Sep 15, 2009 Download for free at http://cnx.org/content/col11069/1.1
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