Calculating the Width of a Valley Using Echo Time Delay

In summary, the problem involves determining the width of a valley based on the time it takes for the sound of a rifle to reach two parallel vertical walls and echo back. The speed of sound is known to be 340 meters per second. To solve the problem, a diagram can be drawn to isolate the time required for sound to span the valley, which is half the sum of the two echo times. The relevant equations are not known, but the speed of sound may have to be multiplied by 2.
  • #1
tdk
13
0

Homework Statement



"A rifle is fired in a valley with parallel vertical walls. The echo from one wall is heard 2.0 s after the rifle was fired. The echo from the other wall is heard 2.0 s after the first echo. How wide is the valley?

Homework Equations



I don't know any relevant equations. v=wavelength x frequency? Do I have to convert something into decibels?

The Attempt at a Solution



time=2 s
distance=?
.
 
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  • #2
No nothing that cpplex--just that the speed of sound is 340meters/sec. Hint: to avoid simple errors, draw a picture of the reflecting sound waves so as to include all the distances.
 
  • #3
But I don't understand how you apply the speed of sound to the problem. Do you multiply it by 2?.
 
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  • #4
know leave the speed alone and as i suggested draw a diagram. In this case, try to isolate the time requires for sound to span the valley. Hint its 1/2 the sum...
 
  • #5
alright pugfug, I told you I unclicked the "Automatically parse links in text" and that's why the link wasnt clickable anymore. And now everytime I post I unclick it so it doesn't come up as a link. Do you understand that? I don't get why I can't post here if the link isn't even clickable, what's the harm?

Thanks Denverdoc I'll try that.
 
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1. What is the decibel level of a rifle sound?

The decibel level of a rifle sound can vary depending on the type of rifle and ammunition used. On average, a rifle sound can range from 140-190 decibels (dB), with larger calibers producing louder sounds.

2. How far can a rifle sound travel?

The distance a rifle sound can travel also depends on the type of rifle and ammunition. On average, a rifle sound can travel up to 1-2 miles, but this can be affected by environmental factors such as wind and terrain.

3. Why does a rifle sound louder in enclosed spaces?

In enclosed spaces, the sound waves from a rifle are confined and bounce off the walls, creating a stronger and louder sound. This is known as reverberation and can increase the perceived loudness of a rifle sound.

4. Can exposure to rifle sound cause hearing damage?

Yes, exposure to loud rifle sounds can cause permanent hearing damage. The Occupational Safety and Health Administration (OSHA) recommends a maximum exposure to a rifle sound of 140 dB for a brief period. Prolonged exposure to sounds above 85 dB can cause permanent damage to the ears.

5. Are there any regulations for controlling rifle sound levels?

Yes, there are regulations in place to control the noise levels of firearms. The National Firearms Act (NFA) regulates the use of silencers on firearms, which can help reduce the sound of a rifle. Additionally, some states have specific laws regarding the use of firearms in residential or urban areas to minimize noise disturbances.

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