Question

What are the first 3 frequencies for a pipe of length 2 m that is open at one end and closed on the other? Draw what these first three waves look like

Answer 1

@PsiSquared do I use the same equation \[L=n \lambda /2 \] and find \[\lambda \] ??

Answer 2

where n=3

Answer 3

\[L=\frac{ n \lambda }{ 4 }\]

Answer 4

The equation I gave is for a pipe that is open on one end and closed on the other.

Answer 5

ooh right.. didnt even pay attention to that

so lambda= (4x2)/ 3
lambda = 2.6

Answer 6

If we solve the equation I gave you for wavelength we get:\[\lambda =\frac{ 4L }{ n }\]The first three frequencies are going to be at n=1, n=2, and n=3. L is constant and equal to 2m.

Answer 7

is lambda the same as frequency?

Answer 8

Oops. Lambda is wavelength. I didn't pay attention to the problem. The equation you need is:\[f=\frac{ nv _{S} }{ 4L }\]where f is frequency and vs is the speed of sound in air.

Answer 9

okay.. not that makes sense. So for these equation v is always 343 m/s

Answer 10

Yes, the speed of sound in air (at STP at sea level) is 343m/s.

Answer 11

okay thank you!

Answer 12

Sure.