A travelling wave, y = Ym sin(2n x/A - 2n ft), is sent along a horizontal string, as indicated in the diagram. The string consists of two sections with linear mass densities, 1 and u2, respectively, and u2 > 1. The tension in the string everywhere has the value T. The speed of the wave in the lighter section of string is v, as shown. Which of the following statements correctly describes the wave when it has entered the heavier section of string, with density u2? a. The wave is moving faster, with speed v2 = ( mu 2 > mu 1) v b. The frequency is lower, with value f2 = f ( mu 1/ mu2 )^1/2 C. The wavelength is shorter, with value lambda 2 = lambda ( mu 1/ mu 2)^1/2 d. The wavelength is longer, with value lambda 2 = lambda ( mu 2/ mu 1) ^1/2