6. 1. Yes 2. No Does the wind affect the pitch of a factory whistle you hear on a windy day?
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8. Let’s explore Doppler effect for sound with demos and applets http://www.falstad.com/mathphysics.html ripple Nerf Doppler Demo Very good animation http://physics-animations.com/Physics/English/waves.htm Relative movement between source and receiver DOES change the frequency and wavelength Does NOT change the wave speed Pay attention to things like frequency, wavelength, and wave speed during applets
9. Is the frequency of a sound wave affected by bouncing off moving surface? This effect is used by some bats in echolocation! Can determine whether insect is approaching Can detect rapidly beating wings of insects Big eared Townsend Bat, Nevada Bureau of Land Management
10. Is the frequency of a sound wave affected by bouncing off moving surface? This effect is used in ultrasonography! Doppler shift in sound frequency reveals blood velocity User:Ekko on wikipedia (above) also: http://www.youtube.com/watch?v=L88hNMak4Go
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17. So, you can’t have waves in space, right? http://www.youtube.com/watch?v=3drcpE-0Inc
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20. There can be constructive or destructive interference Constructive Interference “ In Phase” Destructive Interference “ 180 degrees out of phase” Remember the wave table demo with Ashley on Tuesday? This interference happens with sound waves as well.