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?
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