Sound Travel Time Calculation for Distant Listeners

Click For Summary

Homework Help Overview

The discussion revolves around a problem comparing the travel times of sound and radio signals from a singer to two listeners at different distances. The context includes considerations of sound speed affected by temperature and the speed of light for radio signals.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • The original poster attempts to calculate the time it takes for sound to reach a listener 50m away and seeks assistance for determining the time for a listener 3000km away via radio. Some participants question the assumptions regarding the speeds of sound and light, while others clarify the relevance of temperature to sound speed.

Discussion Status

Participants are actively engaging with the problem, providing insights into the differences between sound and light travel times. There is a recognition of the need to clarify the speed of sound at a given temperature, and some guidance has been offered regarding the formula for calculating sound speed.

Contextual Notes

There is an assumption that the distances to the microphone and radio can be ignored, and the temperature is specified as 20 degrees Celsius, which is relevant for calculating sound speed.

wikidrox
Messages
44
Reaction score
0
First here is the question:

Who will hear the voice of a singer first? A person in the balcony 50m away from the stage, or a person 3000km away at home whose ear is next to the radio? How much sooner? Assume the mic is a few cm from the singer and the temperature is 20 degrees celsius.

Now I was able to calculate how long it would take for the person 50 m away to hear it, but I don't know how to find out how long it will take for the second person to hear it. Please help me. Which equation do it use?
 
Physics news on Phys.org
The radio signal travels at the speed of light. I take it you are to assume that the singer's lips are close enough to the microphone and the hearer's ear is close enough to the radio that you can ignore those. The temperature is relevant to the speed of sound but not the speed of light.
 
Shoot! I think I did it wrong. What would the speed of sound be at 20 degrees? I just thought the speed of sound would be the same as the speed of light. I guess I was wrong.
 
wikidrox said, "I just thought the speed of sound would be the same as the speed of light."

Not quite. Light travels about a million times faster than sound!
 
Speed of Sound = 332 + 0.6T

T = temperature in degrees celsius.
 

Similar threads

Distance needed to walk in order to hear local maximum
  • · Replies 27 ·
Replies
27
Views
5K
Pot falls down toward a man: How long before we warn him?
  • · Replies 7 ·
Replies
7
Views
2K
Tension Calculation for a Vibrating Violin String
  • · Replies 4 ·
Replies
4
Views
3K
Graduate Duration of electromagnetic disturbance
  • · Replies 10 ·
Replies
10
Views
2K
High School What sound frequencies can pass through a hole in a wall?
  • · Replies 31 ·
2
Replies
31
Views
5K
Waves & Optics: Bright Fringe Width Calculation
  • · Replies 8 ·
Replies
8
Views
5K
Sound waves and the doppler effect
  • · Replies 2 ·
Replies
2
Views
2K
Time of Electron/Proton to Radiate Away Half of Their Energy
  • · Replies 2 ·
Replies
2
Views
4K
Help with Wave Speed Homework: Calculate Travel Time of Wave
  • · Replies 8 ·
Replies
8
Views
2K
Timed freefall + sound to respond from cave
  • · Replies 5 ·
Replies
5
Views
2K