• Support PF! Buy your school textbooks, materials and every day products Here!

Frequency heard, need someone to check

  • Thread starter hodgepodge
  • Start date
  • #1
47
0

Homework Statement



A train is traveling 30 m/s in still air. The frequency of the train whistle is f = 250 Hz. What frequency is head by a passenger on a train moving in the opposite direction at 18 m/s and approaching the first train? The velocity of sound in air is 344 m/s.

Homework Equations



F = [(1(+/-) (Velocity listener)/velocity sound) / (1(+/-) (Velocity source)/velocity sound)] *frequency

The Attempt at a Solution



Since the listener is moving towards the source and the source is moving towards the listener the forumula becomes

F = [(1+(Velocity listener)/velocity sound) / (1 - (Velocity source)/velocity sound)] *frequency

After plugging in the numbers i got 288Hz, is that correct?

it makes sense because the listener would hear a higher frequency b/c the source is moving towards the listener

thanks
 

Answers and Replies

  • #2
47
0
so, is it right?
 

Related Threads on Frequency heard, need someone to check

  • Last Post
Replies
1
Views
6K
Replies
2
Views
1K
  • Last Post
Replies
1
Views
1K
Replies
2
Views
1K
Replies
9
Views
2K
Replies
1
Views
874
Replies
3
Views
2K
Replies
3
Views
1K
Replies
11
Views
1K
Replies
5
Views
2K
Top