How Far Must a Sound Source Move to Create Silence Due to the Doppler Effect?

AI Thread Summary
To determine how far a sound source must move to create silence for an observer due to the Doppler Effect, the focus should be on achieving destructive interference between the two sound sources. The observer's hearing threshold does not necessarily need to be below 20 Hz, as it was not specified. Instead, the key is to calculate the distance required for the waves from the two sources to be out of phase by π radians. This approach will provide the necessary separation for silence to occur. Understanding wave interference is crucial in solving this problem effectively.
beastysk8er
Messages
2
Reaction score
0

Homework Statement


Two adjacent sources each emit frequency 800 hz in air (340 m/s). how far would source 1 have to be moved so an observer in front of the sources would hear no sound? .321 .213 .123 or .312.


Homework Equations


f' = f/(1+ vsource/vsnd)


The Attempt at a Solution



i tried to calculate wavelength so that the frequency is below 20 hz (human limit) and figure it out from there but I am stuck? please help, thank you
 
Physics news on Phys.org
The observer wasn't specified to be human...so we cannot assume that we would have to take it so that the frequency is below 20Hz. Rather, what you should do is find the distance of separation between the 2 sources so that the waves they emit destructively interfere (the waves are out of phase by pi).
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Doppler effect and beat frequency
Replies
3
Views
2K
How do you calculate wind speed using the Doppler effect?
Replies
4
Views
3K
Beats calculation/Doppler Effect
Replies
1
Views
2K
Spring and Microphone (Doppler Effect...?)
Replies
7
Views
3K
Doppler effect train frequency question
Replies
4
Views
2K
Doppler Effect: Velocity of a train
Replies
4
Views
2K
Doppler effect (source and detector moving together)
Replies
4
Views
2K
Problem on Doppler effect and sound level
Replies
1
Views
2K
Calculating frequencies with the Doppler Effect
Replies
1
Views
3K
Doppler effect and signs of the equation
Replies
3
Views
2K

Hot Threads

Recent Insights

Back
Top