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

(b) Determine the phase constant `phi`, and write a general expression for the wave function.

Options

A. `(pi)/(2), cos(16pit-(pi)/(20)x)`
B. `0, sin(16pit-(pi)/(20)x)`
C. `(pi)/(2), sin(16pit-(pi)/(20)x)`
D. `(pi)/(4), sin(16pit-(pi)/(20)x+(pi)/(4))`

Answer

A

Explanation

Initial phase constant is `(pi)/(2)`, `y=Asin(omegat-kx)`