# Waves, finding frequency, wavelength, and speed

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

## Homework Statement

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

## Homework Equations

D(x,t) = A sin[2π (x/λ -t/T) + Φ]

## The Attempt at a Solution

I have no clue, the answers are:

11.5 Hz
1.14 m
13.1 m/s

## Answers and Replies

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?

Thanks!

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