Timmy sits at the beach and reads a book. He notices the sounds of the waves and looks up to see the waves crashing softly on the warm shores. How can he find the frequency or period of the waves?

   As you probably have seen in the ocean or a lake, the stronger the wind, the higher the waves. The period and wavelength can be expressed in terms of their reciprocals, the wave frequency ω = 2(pi)/T, and the wave number κ = 2(pi)/λ.

Explanation:     To find the period, we solve for T=1f, given the value of the frequency (f=2s−1). T=12 s−1=0. 5 s. Since one definition of wavelength is the distance a wave has traveled after one complete cycle (or one period), the values for the wavelength (λ=0.9m) as well as the frequency are given.