# Homework Help: Speed of Ocean Waves

1. May 14, 2010

### roam

1. The problem statement, all variables and given/known data
Ocean waves with a wavelength of 120 m are coming in at a rate of 8 per minute. What is their speed?

3. The attempt at a solution

$$\lambda = 120$$

They are coming in at a rate of 8 per minute, that is 8 in 60 seconds. So the period is

$$T=\frac{8}{60}=0.13$$

Now we find frequency

$$f=\frac{1}{T}=\frac{1}{0.13}=7.5$$

$$v=f \lambda = 120 \times 7.5=900$$

But this is wrong. It is far larger than the actual answer! What did I do wrong?

2. May 14, 2010

### rock.freak667

8 per minute would be the frequency, not the periodic time I believe.