4/6/09
Post date: Apr 06, 2009 11:47:16 AM
Bell Ringer: Why can you hear someone who is around a corner from you?
Wave speed
Depends on what type of wave
Depends on properties of the medium
molecules that are closer together transmit waves faster
Gases - farthest apart, so slowest waves
Liquids - closer together, so faster waves
Solids - closest together, so fastest waves (try tapping on desk with ear pressed to it... do you hear it better with your ear to the table or the one that's not on the table?)
Light has definite speed = 300,000,000 m/s in a vaccuum.
Doppler effect
Waves move at a certain speed, regardless of how fast the wave source is moving
Waves ahead of source get squeezed together for a higher pitch, waves behind get spread apart for lower pitch
Page 522 for picture and explanation
Example - Moving chimes
These animations will help you visualize this
Wave Interactions
Reflection - waves bound off a surface at the same angle as they hit it at
Diffraction - waves bend around the edge of an object
Refraction - waves change speed and get bent as the go through a surface
Interference - waves combine with each other when they occupy the same space, and make a bigger or smaller wave than the original
Write a 1-page summary of these behaviors which includes a description and examples of each