Question

A girl on the beach sees 8 waves pass in 4 s. If the wavelength of each

Answer 1

Velocity = frequency x wavelength

              = $\frac{8}{4}$ x 1.2

              = 0.6 m/s

Answer 2

Answer:

The velocity of wave is 2.4m/s.

Explanation:

First, find the frequency using the formula :

$f = \frac{1}{t}$

Let t = 4,

$f = \frac{1}{4}$

$f = 0.25Hz$

Next, given that each wave is 1.2m and there are 8 waves so the wavelength is :

$λ = 1.2 \times 8$

$λ = 9.6m$

Lastly, you have to use velocity formula :

$v = f \times λ \:$

Let f = 0.25Hz,

Let λ = 9.6m,

$v = 0.25 \times 9.6$

$v = 2.4$

(Correct me if I am wrong)