# Waves, finding frequency, wavelength, and speed

1. Aug 24, 2007

### aliaze1

I am assigned the even problem for homework, but I am lost, so I found an odd problem with the same type of question and has the answer.... I just need to know how the calculations are done

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

The displacement of a wave traveling in the negative y-direction is D(y,t)=(5.2cm)sin(5.5y+72t), where y is in m and t is in sec. Find the frequency, wavelength and speed of the wave

2. Relevant equations

D(x,t) = A sin[2π (x/λ -t/T) + Φ]

3. The attempt at a solution

I have no clue, the answers are:

11.5 Hz
1.14 m
13.1 m/s

2. Aug 24, 2007

### nicktacik

Well I'll help get you started.

By comparing the two equations, you know that

$$5.5 = \frac{2\pi}{\lambda}$$

So you can easily find the wavelength.

How can you find the frequency in a similar manner? What is the relationship between frequency and period? When you have the frequency and wavelength, what is the relationship between those and velocity?

3. Aug 24, 2007

### aliaze1

Thanks!

Last edited: Aug 25, 2007