# Standing Waves on a String (Melde's Experiment)

The problem is as follows:

"A string exhibits standing waves with 4 antinodes when a mass of 200 g is hanging over the pulley (see attached figure). What mass will produce a standing wave pattern with 6 antinodes?"

The equations that I have found in the relevant section of the text are as follows:

$$v=\sqrt{\frac{T}{\mu}}$$

$$v=f\lambda$$

$$f=\frac{1}{\lambda}\sqrt{\frac{T}{\mu}}$$

$$T=mg$$

$$\frac{1}{n}=\frac{1}{Lf}\sqrt{\frac{T}{\mu}}=[\frac{1}{Lf}\sqrt{\frac{g}{\mu}}}]\sqrt{m}$$

Where...
T = tension in the spring as supplied by the weight of the hanging mass
mu = linear density of the string
lambda = wavelength
f = frequency of oscillation
m = mass suspended from spring
g = gravitational constant
L = length of the string

I've attached the diagram referenced above for further illustration.

http://img180.imageshack.us/img180/3735/sc002c9a37ww1.th.jpg [Broken]

I have no idea where to even begin with the problem given the lack of information provided by the question.

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