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.

weather forecasts are done by collecting data about the current state of the atmosphere mainly the temperature, humidity and wind and using meteorology, to determine the atmosphere that evolves over time. the h and l mean the high and low pressure. the red strip is a warm front. the blue strip is a cold front. the blue and red strip is a stationary front. the purple strip is a occluded front.

explanation:

d.7.5cm is your answer