kaw energy and_energy_conversions
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Energy and Energy Conversion
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© EDMAN YOST, J. (1999), Copyright Chaos - An Educator's Guide to Copyright Law and “Fair Use”, Intel Teach to the Future CD
Lesson 1
OP15 Define and give the units for energy.- also give examples of energy in everyday experience.
OP18 Explain why the sun is considered our primary source of energy and how this is important in food production and energy supply.
OP21-a Identify different forms of Energy
What is Energy?
• Energy is all around us.
– It can be heard as sound.
– It can be felt as wind.
– It can be seen as light.
What is Energy?
• We define Energy as the ability to do work. • It is measured in Joules (J) or Newton Meters (Nm)• We have energy if we can move something.
• When the golfer swings he moves:o The Clubo The Ballo Himselfo The Air
Forms of Energy
• Energy can be stored in many forms:
—Potential Energy
—Kinetic Energy
—Heat Energy
—Chemical Energy
—Sound Energy
—Electrical Energy
—Magnetic Energy
—Solar Energy
—Nuclear Energy
Potential Energy• Potential Energy is stored energy a body has due to its
position.
• An object that has been raised above its resting place under gravity has potential energy:
e.g. Weight held at a height
• Potential Energy is stored in a stretched spring
Kinetic Energy• Kinetic energy is stored in a body that is
moving.
• Cars and Aeroplanes have Kinetic energy because they can move people and goods.
Heat Energy
• Heat energy can also be used to move things.
• Heat energy causes the alcohol to rise in a thermometer.
• Heat causes warm air to rise making hot air balloons go up.
Chemical Energy• Chemical energy is stored inside materials in chemical
bonds holding them together.
• The food we eat contains stored chemical energy
• This provides us with the ability to move and do work.
• Chemical energy is released when fuel such as coal and oil are burned.
Sound Energy
• Sound stores energy which causes our eardrums to vibrate so that we can hear.
• Sound energy can cause avalanches.
Electrical Energy
• Electrical Energy is due to moving charges.
• Electrical Energy can be seen all around us:
- When we flick the light switch
- When we turn on the television
Magnetic Energy
• Magnets have the ability to move things.
• They can cause paper clips to move towards them.
Solar Energy• The Suns light is our most important
source of energy.
– The sun makes plants and crops grow providing us with food.
– When plants decay over many years turf, coal and oil etc are formed.
- Solar cells can be used to store energy which provide heat and electricity.
Nuclear Energy• This is the energy released when the nuclei of atoms
split (fission) up or join together (fusion).
• Fission:
When atoms are split in a nuclear reactor energy is released to make steam which moves large turbines that make electricity
• Fusion:
When atoms are joined together in a nuclear reactor energy is released.
Lesson 2
OP16 Classify sources of energy as renewable or non-renewable.
OP19 List the advantages and disadvantages of different energy sources, including nuclear sources of energy, as part of the solution to national energy needs
Sources of Energy• There are two groups of energy sources:
– Non-renewable sources • Fossil fuels
– Renewable sources• Solar Energy• Hydro-Electricity• Nuclear Energy• Wind Energy• Tidal and Wave Energy• Biomass Energy• Geothermal Energy
Fossil Fuels• Plants and organisms
absorbed energy from the sun and decayed over millions of years.
• This was compressed over a long period of time and became oil, coal, gas and turf.
• Advantages:– High concentration of
energy.• Disadvantages:
− Causes gases to be sent into the atmosphere causing pollution.
− Contributing to Climate change.− Running out.
Solar Energy• Solar Energy is Energy
from the sun.
• Advantages:– Renewable.– Can heat houses.– Can produce electricity.– Doesn’t cause pollution
• Disadvantages:− Expensive− Not possible to produce as much electricity as a
generating station without covering many square km with solar cells.
Hydro-Electricity• Hydro-electricity is energy
from the potential and kinetic energy of water.
• Advantages:– Renewable.– Produces electricity.– Doesn’t cause pollution– Cost efficient.
• Disadvantages– Causes flooding.– Destroys habitats for
plants and animals
Nuclear Energy• This is energy from
making or breaking nuclear bonds.
• Advantages:– Renewable– Can be produced
in large amounts.– Relatively cheap.
• Disadvantages:– Radioactive waste is harmful or even deadly.– Radiation from waste can last for hundreds and thousands
of years.– Not possible to dispose of waste without causing damage
to future generations?
Wind Energy• Wind energy is from the kinetic
energy of the wind.• Wind farms consist of vertical
masts with large propellers that turn in the wind and produce electricity.
• Advantages:– Renewable.– Doesn’t cause pollution.– Produces electricity.
• Disadvantages:
− More than a thousand turbines are needed to produce the same amount of electricity as a fossil fuel generator.
− They change the look of the countryside and can be noisy.
Tidal & Wave Energy• This is generated by the
movement of tides and waves.• When the tide goes in and out
and when waves move up and down:– huge volumes of water move. – this movement can be used to
power a turbine to produce electricity.
• Advantages:− Renewable− Doesn’t cause pollution.
• Disadvantages:− Converting to electricity is difficult.
Biomass• This is the chemical energy stored in
fast growing plants.
• Sugar cane and oil-seed rape can produce alcohol and methane.
• Methane is ‘natural gas’ and can be used for heating and cooking.
• In Brazil alcohol is used as fuel in cars instead of petrol.
Geothermal Energy• This comes form the heat in
the earth beneath the planet’s surface.
• In Iceland hot water springs up naturally from the ground (in geysers) and is used to heat buildings.
• In some countries, two deep holes are drilled in the ground.– Cold water is pumped down
one.– It comes back as hot water
from the other.
National Energy Needs• Demand for energy in Ireland from
1990-2000 grew by over 60%.
• Still increasing at 3% per year.
• 100’s of trillions of joules needed each year.
• ESB (electricity supply board) runs 23 fossil fuel generating stations and 3 renewable generating stations.
• Expensive - need to look towards renewable energy sources.
Lesson 3
OP17 State the principle of conversion of energy.
OP20-b Carry out simple experiments to show the following energy conversions:
a. chemical energy to electrical energy to heat energy.
b. electrical energy to magnetic energy to kinetic energy.
c. light energy to electrical energy to kinetic energy.
OP21 Give examples of energy conversion from everyday experience.
Principle of Conservation of Energy
• Energy is involved in every physical change.
• Energy is constantly changing from one form to another
e.g. from potential to kinetic as the car moves down the ramp
Energy is neither created nor destroyed but can be converted from one form to another.
Laboratory Safety Rules1. Do not enter the laboratory without permission.
2. Do not use any equipment unless permitted to do so by your teacher.
3. Make sure you know exactly what you are supposed to do. If in doubt ask your teacher.
4. Make sure you know the position of all safety equipment in the laboratory, e.g. the fire extinguishers, first-aid equipment, etc.
5. Always wear eye protection or gloves when instructed to do so.
6. Long hair must be tied back during practical classes.
7. Place your bag and other personal items safely out of the way.
8. Never handle any chemicals with bare hands.
9. Nothing must be eaten, tasted or drunk in the laboratory.
10.Any cut, burn or other accident must be reported at once to your teacher.
Laboratory Safety Rules11. Always check the label on the bottle is exactly the same as the
material you require. If in doubt, ask the teacher.
12. Any chemical spilled on the skin or clothing must be washed at once with plenty of water and reported to your teacher.
13. Test tubes should never be overfilled. When heating a test tube ensure that the mouth of the test tube is pointed away from yourself and everyone else.
14. All equipment should be cleaned and put back in its correct place after use.
15. Always wash your hands after practical work.
16. Students should behave in a responsible manner at all times in the laboratory.
Experiment 23AConverting Electrical energy to Magnetic energy to Kinetic
energy.Method:
1. Attach end of wire to a battery.
2. Wind wire around a nail and connect to other terminal of the battery.
3. Place the nail close to a number of paperclips.
Result:
The paper clips move towards the nail.
Conclusion:Chemical energy in battery Electrical energy in the wireElectrical energy in wire Magnetic energy in the nailMagnetic energy in nail Kinetic energy in paper clips
Experiment 23BConverting Light energy to Electrical energy to Kinetic energy.
Method:1. Attach end of wire to a solar panel
and then to the terminal of motor which has a fan attached.
2. Connect the wire between the other terminal of the motor and the solar panel.
3. Cover the solar panel.Result:
The fan spins when light falls on the solar panel.
Conclusion:
Light energy from the solar panel Electrical energy in the wire
Electrical energy in wire Kinetic energy in the motor.
Experiment 23CConverting Chemical energy to Electrical energy to Heat energy.
Method:
1. Connect the battery, bulb and switch as shown in the diagram.
2. Close the switch and place the thermometer bulb on the light bulb.
Result:
The thermometer shows an increase in temperature of the light bulb
Conclusion:
Chemical energy from battery Electrical energy in the wire
Electrical energy in the wire Heat energy in the light bulb
Quiz time
1. If a man pulls the lever where does his energy come from?
• A: The man• B: The man’s last
meal.• C: The Sun• D: Gravity
Quiz time2. When the lever is pulled the
electric motor starts turning. What energy conversion is happening here?
3. What energy does the cabin have when it is held at its max height?
4. What energy does it have as it is being lowered?
Quiz time
5. Name two harmful side effects that the burning of coal may have on the environment.
6. Give two energy changes that take place at hydro-electric generating stations.
(a.) ……………………energy to……………......energy.
(b.) ……………………energy to…………………energy.
7. Give six examples of energy doing work or being converted form one form to another.
Exploring Science textbook Junior Certificate Science Syllabushttp://sohowww.nascom.nasa.gov/data/LATEST/current_eit_304.gifhttp://www.bestanimations.com/homeoffice/Lights/Bulbs/Bulbs.htmlhttp://www.cs.washington.edu/homes/cjayant/graphics/final/drum_animation.gifhttp://www2.scc-fl.edu/lvosbury/images/SpringStretchAnNS.gifhttp://www.ddart.net/science/physics/physics_tutorial/Class/energy/u5l1b1.gifhttp://www.virted.org/WEATHER/transthermometer_standin.gifhttp://www.free-animations.co.uk/transport/hot_air_balloons/images/hot_air_balloon_8.gifhttp://www.free-animations.co.uk/food/meals/meals_1.htmlhttp://www.suntrek.org/images/hem-powerstation-animating.gifhttp://www.raisingdeafkids.org/graphics/art/animated-ear.gifhttp://cabluey.files.wordpress.com/2008/03/mountain-avalanche1.gifhttp://www.hydro.com.au/handson/students/images/switchfin.gifhttp://www.zerowattstandby.com/HowItWorks.gifhttp://www.teachnet-lab.org/ps101/bglasgold/magnetism/magnet_med_clr.gifhttp://www.free-animations.co.uk/nature/flowers/flower_2.htmlhttp://microcosm.ws/resources/solar_logo_animated.gif
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