(A)Write the expression for y as a function of x and t in SI units for a sinusoidal wave traveling along a rope in the negative x direction with the following characteristics: A = 7.00 cm, = 70.0 cm, f = 4.00 Hz, and y(0, t) = 0 at t = 0. (Use the following as necessary: x and t.)

(B)Write the expression for y as a function of x and t for the wave in part (a) assuming y(x, 0) = 0 at the point x = 20.0 cm. (Use the following as necessary: x and t.)