# Homework Help: Violin String Wavelength

1. Feb 25, 2014

### omiexstrike

I am doing this problem:

(a) Find the speed of waves on a violin string of mass 800 mg and length 22.0 cm if the fundamental frequency is 920 Hz. (b) What is the tension in the string? For the fundamental, what is the wavelength of (c) the waves on the string and (d) the sound waves emitted by the string? (Take the speed of sound in air to be 343 m/s.)

I completed parts a), b), and c), however, I don't know what to do for d).

a)

wavelength = 2L
= 2 (0.22m) = 0.44 m
f= 920 hz

L = wavelength/2
v = f(wavelength)
v=2Lf
= 2(0.22)(920) = 405 m/s

b)

T=(2lf)^2(m/L)

T= 596N

c) wavelength = 2l
= 2 (0.22m) = 0.44m --> 44.0 cm

d) ?

The answers are : a) 405 m/s b) 596 N c) 44.0 cm d) 37.3 cm

I don't know how to arrive for the answer in d).

Thanks for any help.

2. Feb 26, 2014

### ehild

What is the frequency of the sound wave in air?

ehild

3. Feb 26, 2014

### hilbert2

Does the equation $\lambda \nu = c$ look familiar?

4. Feb 27, 2014

### omiexstrike

I got it, thanks guys. =)

5. Apr 7, 2017

### Bihaag

I guess We can use f=v/2L