Three pieces of string, each of length L, are joined together end-to-end, to make a combined string of length 3L. The first piece of string has mass per unit length μ1, the second piece has mass per unit length μ2=4μ1 and the third piece has mass per unit length μ3=μ1/4.
a. If the combined string is under tension F, how much time does it take a transverse wave to travel the entire length 3L? Give your answer in terms of L, F and μ1.
b. Does your answer to part (a) depend on the order in which the three piece are joined together? Explain.