# Shape of wave

1. Oct 13, 2016

### Aliasa

1. The problem statement, all variables and given/known data A travelling wave on a string is described by , 0.0050 sin[4.0 (rad/s) t + 0.50 (rad/m)x] . (a) Does this wave retain its shape as it travels? (b) In what direction does the wave travel? (c) What is the wave travelling speed?

2. Relevant equations
None.

3. The attempt at a solution
My only concern is regarding part a. It is a 3rd year university course, and the rest of the assingment including this qustion is pretty basic. However, I do not understand if I am missing something regarding retaining of shape by the wave. Is there some ratio for k and w, which if violated the wave no longer retains the shape? Clearly, there is no information provided to assume anything like formation of a standing wave. Superficially, it seems the answer is a yes, but I am not sure. Nothing about it in lecture notes either..

2. Oct 13, 2016

### drvrm

why do you think it may not retain its shape?
write out the equation for travelling waves and see how it moves after say full period T and a full wavelength Lambda

3. Oct 13, 2016

### Aliasa

I thought it would retain its shape. y = A sin (kx-wt)
It's just periodic.

4. Oct 13, 2016

### drvrm

in what direction your wave written above moves? at x=0 y= - A sin wt but in the problem quoted above you have a factor +wt,so it should make a difference ?

5. Oct 13, 2016

### drvrm

in what direction your wave written above moves? at x=0 y= - A sin wt but in the problem quoted above you have a factor +wt,so it should make a difference ?