Chapter 17 - Linear Superposition Flashcards
In Figure 17.7, suppose that the separation between speakers A and B is 5.00 m and the speakers are vibrating in phase. They are playing identical 125-Hz tones, and the speed of sound is 343 m/s. What is the largest possible distance between speaker B and the observer at C, such that he observes destructive interference?
A little tricky one
But basically you want to find the wavelength (2.744) (easy part) and then divide by 2 so its a half multiple and then you have (1.372)
path length is AC - BC
to make all terms in term of BC, AC by the pythagorean theorem is equivalent to AC=sqrt(25+BC^2)
sub into
1.372 = AC-BC
and solve for BC which should come out to 1.372
Path length differences for constructive and destructive interferences starting in and out of phase
IN PHASE (likely to get this)
Constructive - integer # of wavelengths
Destructive - half integer # of wave lengths
Just remember opposite for out of phase
For solving these problems just compare the distance and the wavelength
The frequencies of standing waves for tube open at both ends and tube closed at both ends
Open at both ends
Max amp at both ends so antinodes
Open at only one end
Closed end is node and open antinode, only occurs at odd harmoincs
