(a1 Write an equation describing a sinusoidal transverse wave traveling on a cord in the positive direction of a y axis with an angular wave number of 80 cm'l. a period of 0.18 s. and an amplitud e of 2.5 mm. Take the transverse direction to be the z direction. (b}What is the maximum transverse speed of a point on the cord? a}z-n v 'sin{n v 'y v n v b} n v