The speed of longitudinal waves traveling in a long, solid rod is given by v = Y/p,

Question:

The speed of longitudinal waves traveling in a long, solid rod is given by v = √Y/p, where Y is Young’s modulus and is the density of the solid. If a disturbance has a frequency of 40 Hz, what is the wavelength of the waves it produces in
(a) An aluminum rod and
(b) A copper rod?