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Waves and sound

  • Thread starter Xoloti
  • Start date
  • #1
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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
 

Answers and Replies

  • #2
berkeman
Mentor
56,812
6,778

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:
 
  • #3
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0
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!
 
  • #4
berkeman
Mentor
56,812
6,778
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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