Section 2- Waves And The Electromagnetic Spectrum Flashcards
transverse wave
- perpendicular
- vibrations go up and down
- most waves are transverse
Eg. All electronic waves, S waves, ripples and waves in water
longitudinal wave
•the vibrations are parallel to the direction the wave travels
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Examples include sound waves and p waves
equation for wave speed
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how to measure the speed of sound
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how to find speed of waves in solids
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refraction(waves)
Waves changing direction at a boundary
definition of absorbed
If the wave is absorbed the wave transfers energy to the material’s energy stores
Often transferred to a thermal store which leads to heating (how microwaves work)
definition of transmitted
If a wave is transmitted the waves carries on travelling through the material.
This often leads to refraction
definition of reflected
If a wave is reflected this means the ray is neither absorbed or transmitted but instead ‘sent back’
This is how echoes are created
what causes sound waves?
Caused by vibrating objects
what type of wave are sound sound waves?
Longitudinal waves
how does sound travel in a gas?
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how does sound travel in a solid?
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how does sound travel in a liquid?
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what are echoes?
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explain how humans hear sound
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explain how ultrasound works
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what are ultrasounds used for?
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infrasound
Sound with frequencies lower than 20Hz
definition of seismic waves
- earthquakes and explosions cause seismic waves
- can be detected with a seismometer
- two main types p waves and S waves
p-waves
- longitudinal
- travel through solids and liquids
- travel faster than S waves
s-waves
- transverse
- only travel through liquids
- slower than p waves
reflection (light)
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definition of refraction
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what happens when the light refracts off a smooth surface?
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what happens when the light refracts off a rough surface?
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how to investigate fraction
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definition of converging/convex lens
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definition of diverging/concave lens
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how does light travel through a convex lens?
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how does light travel through a concave lens?
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how can you increase the power of the lenses?
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definition of virtual image
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definition of real image
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list the electromagnetic spectrum
- radio waves
- microwaves
- infrared radiation
- visible light
- ultra violet
- x-rays
- Gamma rays
which has the longest wavelength in the electromagnetic spectrum?
Radio waves
which has the lowest frequency in the electromagnetic spectrum?
Radio waves
how can EM be used for communication ?
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uses and features of each in the EM spectrum
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which has the shortest wavelength in the electromagnetic spectrum?
Gamma rays
which has the highest frequency in the electromagnetic spectrum?
Gamma rays