Am I overthinking this? (Noise cancelling headphones for airplane noise)

In summary, the conversation discussed the possibility of shifting a wave by 2Pi to get the opposite wave, with further suggestions of shifting by 1Pi or Pi/2. The conversation also mentioned the importance of considering the start and end points of the wave and how a phase shift can be equivalent to negating the expression.
  • #1
Thickmax
31
8
Homework Statement
Am I over thinking this question
Relevant Equations
See below (shown in the question)
1625957474706.png
Can I just shift the wave over by 2Pi to get the opposite wave?
 

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  • #2
Thickmax said:
Homework Statement:: Am I over thinking this question
Relevant Equations:: See below (shown in the question)

Can I just shift the wave over by 2Pi to get the opposite wave?
How will a shift of 2pi give you anything different from the original wave?
 
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  • #3
haruspex said:
How will a shift of 2pi give you anything different from the original wave?
Shift it by 1pi then?
 
  • #4
Thickmax said:
Shift it by 1pi then?
Pi/2?
 
  • #5
I'd suggest drawing s(t), sheadphones and their sum.
 
  • #6
Thickmax said:
Shift it by 1pi then?

Thickmax said:
Pi/2?
Don't just guess. Figure it out.
 
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  • #7
the answer is negative the same equation...start points and end points will be the same?

Shifting the wave will move the start and end points by either (2pi, pi or pi/2)
 
  • #8
I repeat my original hint: draw s(t) and shead(t) (3, 4 of them?) and add. One of them should be close to zero.
 
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  • #9
Thickmax said:
the answer is negative the same equation
Right, so that is a valid answer to the question.
Thickmax said:
Shifting the wave will move the start and end points by either (2pi, pi or pi/2)
Not sure what you mean by that. The equation does not have endpoints. It expresses the amplitude for all times and all locations.
If you mean shifting the entire wave, yes, there is a phase shift that is exactly equivalent to negating the expression: ##\sin(\theta)=-\sin(\theta+\phi)## for some ##\phi##. You really should be able to say immediately what that value is! Consider the sines of 0°, 90°, 180°, 270°, 360°.

There is one other error in your attempt in post #1. It tells you which variables are allowed in the answer, but you have used one not in the list.
 
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FAQ: Am I overthinking this? (Noise cancelling headphones for airplane noise)

What are noise cancelling headphones and how do they work?

Noise cancelling headphones are a type of headphones that use active noise control technology to reduce unwanted ambient sounds. They work by using tiny microphones to pick up external noise and then producing an opposite sound wave to cancel out the noise.

Will noise cancelling headphones completely block out all airplane noise?

Noise cancelling headphones are designed to reduce the intensity of external noise, but they may not completely block out all airplane noise. They are most effective at cancelling out low-frequency sounds such as engine noise, but may not be as effective at cancelling out higher frequency sounds like people talking or crying babies.

Are noise cancelling headphones safe to use during flights?

Yes, noise cancelling headphones are safe to use during flights. They do not emit any harmful radiation or interfere with the airplane's communication systems. However, it is always a good idea to follow the airline's guidelines and instructions regarding the use of electronic devices during flights.

Do I need to turn on the noise cancelling feature for it to work?

Yes, in most cases, you will need to turn on the noise cancelling feature for it to work. Some headphones have a passive noise cancelling feature, which means they block out noise by physically covering your ears. However, for active noise cancelling headphones, you will need to turn on the feature for it to effectively cancel out external noise.

Do noise cancelling headphones work for all types of noise?

No, noise cancelling headphones are most effective at cancelling out low-frequency, constant noises such as airplane engine noise. They may not be as effective at cancelling out sudden or high-pitched noises, such as a baby crying or someone shouting. However, they can still help reduce the intensity of these noises.

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