From the figure, the phase of the wave is zero; hence, the equation of the wave is y = Asinωt where A is the amplitude (A = 10 cm) and w is the angular frequency. v = Aω cosωt It is given that y = 5 cm; thus, 5 = 10 sinωθ ⇒ ωθ = 30° Therefore, the velocity is v = 10 cm × 2π ×