# How fast is wave travelling from graph

1. Mar 12, 2014

### negation

1. The problem statement, all variables and given/known data

The figure shows the displacement y of a traveling wave at a given position as a function of time and the displacement of the same wave at a given time as a function of position. How fast is the wave traveling?

3. The attempt at a solution

I'm totally lost with this question. How should I approach this?

v = λ/ T

2. Mar 12, 2014

### collinsmark

You've nailed it with your relevant equation. (By that I mean your "v = λ/T" equation is exactly the one you want to use.)

With one of the graphs, you should be able to figure out the wavelength, λ. In other words, answer, "how long is one wavelength?" Still in other words, "how many meters is one period of the wave?"

With the other graph, you should be able to figure out the period of the wave. In other words, answer, "how long does it take (in seconds) for the wave to cycle through one wavelength?" Or, "how many seconds is one period?"

3. Mar 15, 2014

### negation

lamda = 3m
T = 4s
v = 3/4 = 0.75ms^-1

Very sure this is correct.

Last edited: Mar 15, 2014
4. Mar 15, 2014

### collinsmark

'Looks correct to me.