what is a wave? a wave is a disturbance that transfers energy through space and/or some medium....
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What is a wave?• A wave is a disturbance that transfers energy
through space and/or some medium. • There are two main types of waves:– Electromagnetic Waves transfer electric and
magnetic energy.• Can travel through empty space or a medium such as air.• The sun’s energy arrives on Earth as EM radiation.
– Mechanical Waves require a medium to transfer energy.• Cannot travel through empty space.• Examples: Sound waves, water waves, etc.
Wave Characteristics• All EM waves travel at the same speed in a vacuum,
but they have different wavelengths and different frequencies.
• Wavelength - the distance between the crest of one wave and the crest of the next wave.
• Frequency – the number of waves that pass a given point in a certain amount of time.– Higher frequency = more energy– Lower frequency = less energy
• Amplitude – the height of the wave
Electromagnetic Spectrum(EM Spectrum)
Foldable
Goal: Students will create a foldable that will help them understand the
electromagnetic spectrum.
Draw this wave on your paper. Does not need to be exactly the same. The waves do need to get closer together as you move the right.
Add the information above the EM Spectrum diagram
__________ Wavelength__________ Frequency__________ Energy
__________ Wavelength__________ Frequency__________ Energy
Fill in the flaps below.Ra
dio
wav
es
Mic
row
aves
Infr
ared
w
aves
Visi
ble
light
Ultr
avio
let
wav
es
X-ra
ys
Gam
ma
rays
__________ Wavelength__________ Frequency__________ Energy
__________ Wavelength__________ Frequency__________ Energy
Electromagnetic Spectrum
• You will watch a short video about each kind of electromagnetic wave. While watching these videos, write down the following information about the kind of wave. Fold your foldable in half. This information should go underneath the flap of the specific kind of wave. If you are writing down information about radio waves, then flip the radio wave flap up and write down the information about radio waves.1. Relative wavelength2. Relative frequency3. Uses4. Hazards
Microwaves
• Wavelengths are shorter than radio waves• Frequencies are higher than radio waves• Used in radar guns, microwave ovens, cell
phones• No known hazards
Infrared waves
• Wavelengths are shorter than microwaves• Frequencies are higher than microwaves• Used in heat lamps, infrared cameras, and
remote controls• No known hazards
Visible light
• Wavelengths are shorter than infrared waves• Frequencies are higher than infrared waves• White light can be separated into the colors
red, orange, yellow, green, blue, and violet (ROY G. BIV)
Visible light
• Red light has the longest wavelength and shortest frequency of visible light• Violet has the shortest wavelength and highest
frequency of visible light• Uses: We can see it!• No known hazards
Ultraviolet waves
• Wavelengths are shorter than visible light waves• Frequencies are higher than visible light waves
Ultraviolet waves
• Used in bug zappers, black lights, tanning beds, fluorescent bulbs, and in detecting real versus forged documents, money, and credit cards
• Energy is great enough to damage or kill living cells. Can cause sun burn, which may eventually lead to skin cancer.
X-rays
• Wavelengths are shorter than ultraviolet waves• Frequencies are higher than ultraviolet waves• Can penetrate most matter. Used in x-ray machines to
view bones or items in luggage.• Too much exposure can damage cells leading to
cancer or even kill cells.
Gamma rays
• Shortest wavelengths• Highest frequencies• Most penetrating of all waves. Gamma
radiation is used to kill cancer cells.
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