A sinusoidal wave travelling in the positive `x` direction has an amplitude of `15 cm`, wavelength `40 cm` and freqency `8 Hz`. The vertical displacement of the medium at `t = 0` and `x = 0` os also `15 cm`, as shown.

(a) Find the angular wave number, period, angualr frequency and speed of the wave.
(b) Datermine the phase constant `phi`, and write a general expression for the two wave function.

Explanation

`k = (2x)/(lambda) = (2 pi "rad")/(40 cm) = (pi)/(20) "rad" //cm`
`t = (1)/(f) = (1)/(8)s " "omega = 2 pi f = 16 pi "rad" s^(-1)`
`v = f lambda = 320 cm//s `