試題詳解

22. Three sinusoidal waves of the same frequency travel along a string in positive direction of an x axis. Their amplitudes are y₁ ,y₁/ 2and y₁/3 , and their phase constants are 0, π/2, and π, respectively. What is the phase constant of resultant wave?
(A) 30°
(B) 37°
(C) 45°
(D) 53°
(E) 60°