- #1

cheff3r

- 25

- 0

## Homework Statement

The water level in a vertical glass tube (length 1 m) can be adjusted to any position in the tube. A tunning fork vibrating at 660 Hz is held just over the open end of the tube. calculate at what position of the water level will there be resonance (standing waves) in the tube? Assume speed of sound is 330 m/s

## Homework Equations

f=n*v/(4*L) where n is an odd number

I'm guessing I've gone wrong with relevant equations part

## The Attempt at a Solution

My fist assumption is that the end with water in it should be considered to be closed even though in reality some sound would go through the water, is this correct? or should i be treating it like the one on this site http://hyperphysics.phy-astr.gsu.edu/hbase/Class/PhSciLab/restube2.html

anyway so treating it as closed i can use the above formula re-arranged or length

L=4*f/(n*v)

n=1: L = 4*660/(1*330) = 8 m

n=3: L = 4*660/(3*330) = 24 m

n=5: L = 4*660/(5*330) = 40 m clearly all are going to be to big for tube, i also considered different frequencies with no success, it is unlikely my lecture would give a trick question, am i doing something wrong?