Train Whistle Echo: Calculating Distance & Temperature Effects

[Xoloti]

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

 

[berkeman]

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?

 

[Xoloti]

Welcome to the PF.

How does the speed of sound in air change with a change in air temperature?

Higher the temperature faster the speed of sound. Thanks!

 

[berkeman]

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?

 

[Xoloti]

https://www.nde-ed.org/EducationResources/HighSchool/Sound/tempandspeed.htm