Why Is 686 m/s Incorrect in Physics Calculations?

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SUMMARY

The discussion centers on the incorrect calculation of sound distance at 686 m/s based on the formula v = D/T. The user mistakenly assumes that 686 m is the distance from the sound source to the listener without considering the context of the echo and the environment, specifically a rocky cliff. The correct interpretation involves understanding that 343 m/s is the speed of sound, and the distance must account for the round trip of the sound wave. Thus, the user should clarify their position relative to the sound source and the reflective surface.

PREREQUISITES
  • Understanding of basic physics concepts, specifically sound propagation.
  • Familiarity with the formula v = D/T for calculating speed, distance, and time.
  • Knowledge of the speed of sound in air, approximately 343 m/s at room temperature.
  • Contextual awareness of how sound reflects off surfaces, such as cliffs.
NEXT STEPS
  • Research the physics of sound waves and their behavior in different environments.
  • Study the concept of echoes and how distance is calculated in acoustics.
  • Explore the impact of temperature and altitude on the speed of sound.
  • Learn about the principles of wave reflection and refraction in physics.
USEFUL FOR

Students studying physics, educators teaching sound dynamics, and anyone interested in the principles of acoustics and wave behavior.

Bruh23
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Homework Statement
You are standing at some distance from a rocky cliff and shout loudly. You hear the echo 2 seconds later. How far is the rocky cliff? Take the speed of sound in air as 343 m/s and round off your answer to the nearest integer (whole number).
Relevant Equations
v = Distance/Time
I brought time over to the other side and multiplied to get 686 m/s but that wasn't correct
 
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Show your work
 
v = D/T
v*T = D/T*T
343 m/s * 2s = D
D = 686 m
 
686 m is the distance sound travels in 2 seconds. Are you 686 m away from the point where you produced the sound when you hear the echo?
 
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You are doing math blindly, without consideration for context. There is a reason they've told you you're facing a rocky cliff.

Or, more simply: you have not actually answered the question asked. What is the question that was asked?
 
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Why the "Physics of light and sound"?
 
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nasu said:
Why the "Physics of light and sound"?
Likely the name of the chapter OP is studying.
 
1674015095339.png


Can we conclude that you figured it out?
 
nasu said:
Why the "Physics of light and sound"?
It refers to how the OP likes to dress when studying Physics. See their Avatar...

1674245512775.png
 
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