What are electromagnetic waves?
Electromagnetic waves are transverse waves they transfer energy from the source of the waves to an absorber.
What is a good example of an EM wave?
Microwaves transfer energy from the source (the oven) to the absorber (food).
What are the characteristics on the red end of the spectrum
On the red end of the spectrum waves have lower frequency and longer wavelength
What are the characteristics on the violet end of the spectrum
On the violet end of the spectrum the waves have a higher frequency and a shorter wavelength
What part of the spectrum can be seen my the human eye?
Visible light is the only part of the spectrum that can be detected by the human eye
What happems as you move from radio waves to gamma rays in the spectrum?
Frequency will increase from radio waves to gamma rays and wavelength decreases.
What kind of spectrum is the electromagnetic spectrum?
A continuous spectrum
What is a continuos spectrum?
Continuous spectrum means the cut off point between one type of wave and another is not always clear.
Do EM waves need a medium to travel in?
EM waves do not need a medium to travel in, EM waves can travel through a vacuum e.g space.
What are the characteristics of an EM wave in a vaccum?
In a vacuum all EM waves travel at the same speed. At 300,000,000 m/s - 3x10^8 m/s
At what speed do EM waves travel in a vaccum?
3x10^8
What are the 3 ways EM waves effect materials?
1) Absorb
2) Transmit
3) Reflect
Microwaves and food?
Microwaves are absorbed by food which contain water molecules. Microwaves are reflected from metals.
What happens to light waves when interacting diffrent surfaces?
Light waves are absorbed by the black surfaces and reflected from shiny, metallic surfaces.
What does RMIVUXG stand for?
Ronald - Radio
McDonald - Microwave
Is - Infrared
Visiting - Visible light
Ur - Ultraviolet
X - X-ray
Girlfriend - Gamma rays
What are radio waves used for?
Radio waves are used to transmit radio and terrestrial TV signals
What is Terrestrial TV?
Terrestrial TV is not satellite or cable TV. Terrestrial TV is received using an aerial.
Why are radio waves used to transmit radio and terrestrail TV signals?
Radio waves are used because they can travel long distances before being absorbed e.g. by buildings or trees.
What can longer wavelength radio waves also do?
Longer wavelength radio waves can also spread out between hills (diffraction).
What is another special thing about radio waves?
Radio waves can also reflect off a layer of charged particles in the atmosphere (ionosphere)
Why are microwaves used to heat food?
Microwaves are used to heating food - because most foods contain a lot of water molecules
- water molecules absorb the energy of microwaves
The energy causes the temperature of the food to increase
What are 2 main uses of microwaves?
Heating food
Communicate with satellites
Why are microwaves used to communicate with satellites?
Microwaves are used to communicate with satellites in space. Because microwaves can pass through the earth’s atmosphere without being reflected or refracted.
What is infrared and why is it used?
Infrared is emitted by electrical heaters and also is used to cook food in ovens. Because the energy of the infrared is easily absorbed by the surface of objects.
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Forces (P8, P9 & P10) & Equations15
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Equations: Energy P1, P2 & P35
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P1. Conservation & Dissipation Of Energy67
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P2. Energy Transfer By Heating 👩🏼🦲7
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P3. Energy Resources20
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P4. Electrical Circuits109
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P6. Molecules & Matter19
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P7. Radioactivity76
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P8. Forces In Balance22
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P9. Motion25
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P10. Forces & Motion1
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P11. Wave Properties44
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P12. EM Waves43
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Scientific Terms4
