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What do all waves of the electromagnetic spectrum have in common?

They all travel at the same speed through are a vacuum.
They are all transverse.


What are the uses of radiowaves?

They have a very long wave length so they are used in:
- Broadcasting
- Communication


Which end of the electromagnetic spectrum has the longest wave length?

- Radiowaves have the longest wavelength and it gets shorter from there.


Which end of the electromagnetic spectrum has the lowest frequency?

- Radiowaves have the lowest frequency and it gets higher from there. (Gamma rays have the highest frequency)


What are the uses of mircowaves?

- Satellite communication
- Cooking (the microwaves used in cooking are absorbed by the water molecules in food and transfer their energy to other parts of the food)


What are the uses of infared?

Infared is also heat radiation so it can be used in:
- heaters
- night vision equipment


What are the uses of visible light?

- optical fibres
- photography


What are the uses of x-rays?

- Observing the internal structure of objects and materials
- This is used in medical applications (i.e. x-ray machines)


What are the uses of gamma rays?

- sterilising food and medical equipment


What is a useful anagram for remembering the order of the electromagnetic spectrum?

Raul's Mother Is Visting Uncle Xavier's Garden


What are some of the dangers of microwaves?

- internal heating of body tissue


What are the uses of ultaviolet light/

- fluorescent lamps


What are some dangers of infrared?

- Skin burns


What are some dangers of ultraviolet light?

- damage to surface cells and blindness


What are some dangers of gamma rays?

- cancer/ cell mutation


Describe a transverse wave.
Give some examples of transverse waves.

- In transverse waves the vibrations are at 90 degrees to the direction energy is transferred by the wave.
- Ripples on water; all waves on the electromagnetic spectrum.


Describe a longitudinal wave.
Give some examples of longitundinal waves.

- In longitudinal waves the vibrations are along the same direction as the wave transfers energy. It has compressions and rarefactions.
- sound and ultra sound waves; shock waves.


What is the amplitude of a wave?

The height of it from rest (the middle) to crest (the top of the peak).


What is frequency?
What is it measured in?

How many complete waves there are passing a certain point per second.
Measured in hurtz (Hz)


What is the time period?
What is it measured in?

The time is takes for one complete waves to pass a certain point.


How do triangular prisms disperse white light?

Different wavelengths of light refract by different amounts.
A triangular prism does not have parallel boundaries (like a rectangular block does), so the different wave lengths in white light do not emerge parallel, because they have been refracted by different amounts.
This means white light has dispersed into the visible light spectrum and you get the rainbow effect.


What is a way to remember the order of the visible light spectrum? (From the least refracted to the most refracted)

Richard Of York Gave Battle (In) Vain : Red Orange Yellow Green Blue (Infrared) Violet


How does the refractive index of a media affect the speed of a wave that travels throught it?

The higher the refractive index, the slower the wave wil travel.


What is the frequency range of human hearing?

20 - 20000 Hz