what do these pictures have in common?. 2 introduction to waves
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What do these pictures have in common?
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Introduction to Waves
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Waves are everywhere in nature
Sound waves visible light
wavesradio wavesmicrowaveswater waves
telephone chord waves
stadium waves earthquake
waves waves on a
stringslinky waves
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What is a wave?
A wave is a disturbance (source of energy) that travels through a medium from one location to another.
A wave is the motion of a disturbance
Waves transfer energy not matter. The water waves below are carrying energy but are not moving. Waves can only exist as they have energy to carry.
Mechanical Waves
Waves that require a medium to pass through.
A medium is a material through which waves can passGases (air)Liquids (water)Solids (ropes)
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What are two kinds of mechanical waves?
TransverseLongitudinal (Compression)
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Transverse Waves
A disturbance that is perpendicular to the direction of the wave
Ex. Moving a rope up and down.
disturbance
wave direction
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Example of a transverse wave:
Longitudinal (Compression) Wave
The disturbance is parallel to the direction of the wave travel. Ex. Spring toy or SLINKY!
Compression-the coils come together
Rarefaction- the coils spread out
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Example- Longitudinal Wave
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Longitudinal vs. Transverse Waves
The differences between the two can be seen
Properties of Waves
Crest and TroughAmplitudeWavelengthFrequency
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Crest and Trough
Crest-The highest part of a transverse wave
Trough- The lowest part of a transverse wave
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Amplitude-Transverse Wave
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Amplitude- Longitudinal WaveDepends on how dense (bunched) the
medium is at each compression.Coiled spring A has the greater
amplitude.
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Wavelength
The distance between two corresponding parts of a wave.Crest to CrestTrough to Trough
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FrequencyThe number of complete waves that pass
a given point in a certain amount of time.Measured in hertz (Hz)
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HIGH Frequency
LOW Frequency
Review
1. Identify two types of mechanical waves.
1. What is amplitude?
1. If a wave has a high frequency, do the wavelengths become shorter or longer?
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