# Traveling wave question

1. Nov 17, 2004

### nazarip

A string has a linear mass density of 3.4 g/m. When a sinusoidal wave is created on the string with a speed of 32.8 cm/s the displacement of the particles on the string at x=13.3 cm varies with time according to the following equation: y=4.4sin[1.1-3.3 t] cm. Find the frequency.

Well, I am stuck on this question and need a kick in the right direction...

v=f*lambda
angular velocity=2*3.14*f=wave#*velocity

I really dont have a clue as to where to begin...

2. Nov 17, 2004

### James R

The equation of a travelling wave moving in the positive x direction is:

$$y = A \sin(kx - \omega t)$$

where

$k$ is the wave number
$\omega$ is the angular frequency
$A$ is the amplitude.

3. Nov 17, 2004

### nazarip

the equation Im given doesnt have an x variable so am I to assume k= 1.1? or w=-3.3? And if w=-3.3 then the frequency would be a negative number? is that possible?

4. Nov 17, 2004

### James R

You're given x=13.3 cm.

Also, w is not -3.3, but 3.3.

5. Nov 17, 2004

### nazarip

oh ok, thanks for the help.