A sinusoidal wave travelling in the positive x-direction has an amplitude of 15 cm, a wavelength of 40 cm and a frequency of 8 Hz. The vertical displacement of the medium at t = 0 and x = 0 is also 15 cm, as shown in figure.
(a) find the angular wave number k, period T, angular frequency ω and speed v of the wave.
(b) Write a general expression for the wave function.
