promotion image of download ymail app
Promoted
Rosie asked in Science & MathematicsPhysics · 2 months ago

Need help on physics problem?

When the slide of a trombone is extended, the length of the column of vibrating air increases. Since the speed of sound does not vary, we observe that the frequency of the note being played... 

(Don't know whether it increases, decreases, or stays the same.)

4 Answers

Relevance
  • NCS
    Lv 7
    2 months ago

    velocity = frequency x wavelength

    "Since the speed of sound does not vary," increasing the wavelength must DECREASE the frequency.

    • Commenter avatarLogin to reply the answers
  • 2 months ago

    The wave (or at least half of it) must fit into the length of the tube.  If the length is longer then it takes more time to go up the tube and back so it makes fewer cycles in each second.  ie the frequency must be lower.  There are other modes where we fit MORE than one wave into the tube.

    • Commenter avatarLogin to reply the answers
  • 2 months ago

    If the length of the string is L, the fundamental harmonic is the one produced by the vibration whose nodes are the two ends of the string, so L is half of the wavelength of the fundamental harmonic. Hence one obtains Mersenne's laws:

    (Frequency) f = 1/2L√[T/µ]

    where T is the tension (in Newtons), µ is the linear density (that is, the mass per unit length), and L is the length of the vibrating part of the string. 

    =>f is inversely proportional to L

    =>if L increases, f decreases

    =>if L decreases, f increases

    • Commenter avatarLogin to reply the answers
  • 2 months ago

    Longer = lower frequency.  Just like with a guitar string.

    • Commenter avatarLogin to reply the answers
Still have questions? Get your answers by asking now.