Train Whistle Echo: Calculating Distance & Temperature Effects

AI Thread Summary
The discussion revolves around calculating the distance to a reflecting surface based on the time it takes for a train engineer to hear an echo from a stationary railroad whistle. The engineer hears the echo 4.0 seconds later, leading to a calculated distance of 686 meters using the speed of sound at 343 m/s. Participants also discuss how an increase in air temperature affects the speed of sound, noting that higher temperatures result in faster sound transmission. A reference link is provided to support this claim about temperature's effect on sound speed. Understanding these principles is essential for accurately solving similar problems in physics.
Xoloti
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Homework Statement


a)a stationary railroad whistle is sounded. An echo is heard 4.0 seconds later by a train's engineer. If the speed of sound is 343 m/s, how far away is the reflecting surface?
b) If the temperature of the air increased, how would this change your answer?

Homework Equations


d=rt
x=xt/2

The Attempt at a Solution


I got part a right. x=(343*4)/2 =686 because the sound has to travel twice
I do not know part b
 
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Xoloti said:

Homework Statement


a)a stationary railroad whistle is sounded. An echo is heard 4.0 seconds later by a train's engineer. If the speed of sound is 343 m/s, how far away is the reflecting surface?
b) If the temperature of the air increased, how would this change your answer?

Homework Equations


d=rt
x=xt/2

The Attempt at a Solution


I got part a right. x=(343*4)/2 =686 because the sound has to travel twice
I do not know part b
Welcome to the PF.

How does the speed of sound in air change with a change in air temperature? :smile:
 
berkeman said:
Welcome to the PF.

How does the speed of sound in air change with a change in air temperature? :smile:
Higher the temperature faster the speed of sound. Thanks!
 
Xoloti said:
Higher the temperature faster the speed of sound. Thanks!
Really? That may be true, but it's counter-intuitive for me. Do you have a link to a reference that says that? :smile:
 

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