Waves Flashcards
Standing waves
horizontal positions of crests and troughs remaining fixed
If a wave is in phase what are the angles?
0 degrees, 360 degrees, or 2Pi
What are angles for out of phase?
180 degrees or pi radians
What are nodes?
points that don’t vibrate
What are antinodes?
point where amplitude is maximized
What is the distance between two consecutive nodes?
half wavelength
What is sound speed dependent on?
medium’s resistance to compression and its density
If resistance to compression is greater what is the effect on speed of sound?
Faster
If density is than compression of sound what is the effect on speed of sound?
Slower
What medium does sound travel through the fastest?
solid
What medium does sound travel the slowest?
gases
What causes the variances of speed of sound?
temperature, pressure, and humidity
What does the close end of a pipe correspond to in a standing sound wave?
displacement node or no motion
What does the open end of pipe correspond to in a standing sound wave?
antinode
Where does pressure vary most in standing sound wave in a pipe?
Where there is no pressure
Where does motion vary in standing sound wave in pipe?
Where there is constant pressure
For an open pipe, the distance between displacement nodes is equal to what?
whole number of half wavelengths
For a closed pipe, the distance between the displacement node and displacement antinode is equal to what?
Odd number of quarter wavelengths
What are beats?
If two sound waves have slightly different frequencies
What is beat frequency equal to?
difference between frequencies of two original sound waves
What is intensity?
energy wave transmits per second per unit area. Unit is Watts/meters squared
Intensity is inversely proportional to what?
the square of the distance to the source
What is doppler effect?
Difference in frequency that arises whenever a source of waves is moving relative to the detector
If an object is approaching, what is the perceived sound?
higher frequency
If object is receding what is perceived sound?
lower frequency
according to the doppler effect, what changes the speed of sound?
If detector moves toward or away from stationary source
If moving toward the stationary source speed of sound increases or decreases?
Increases
If moving away from the stationary source, the speed of sound decreases or increases?
decreases
If detector is at rest, an increase in wavelength with constant wave speed will result in what for frequency?
Decrease in frequency
