Calculate open pipe length given resonance.

[seker]

Homework Statement

What length of open pipe is needed to give resonance to a 384 Hz sound? Assume the speed of sound to 343 m/s.

Homework Equations

$$f=\frac{nv}{2l}$$

The Attempt at a Solution

I am lost as to how to even start this problem.

 

[tiny-tim]

welcome to pf!

hi seker! welcome to pf!

what is the (shortest) length (of an open pipe) needed to give a particular wavelength?

 

[seker]

This is what I have come up with so far.

$$(384)(l)=\frac{(1)(343)}{2}$$

l=9.45m

 

[tiny-tim]

looks ok!

(btw, do you understand why there's a "2" on the bottom, and would you be able to work it out for yourself in an exam if you couldn't remember the exact formula? )