The graphs below are plots of y(x, t) vs. x for the function y(x, t) = a cos[b(x + vt)], which represents a wave moving to the left along the horizontal axis. Figure (i) represents the wave at time t = 0 and figure (ii) represents the wave at time t = 1.0 s, before the wave has traveled one full wavelength. Here, y and x are in meters. y (m) y (m) (1) (a) What is the amplitude of the wave? m (b) What is the speed of the wave? m/s (c) What is the value of the constant b? m-1 10 15 x (m) W 5 (ii) 12 15 x (m)