A vertical, 1.20-m length of 18-gauge (diameter of 1.024 mm) copper wire has a l00.0-N ball hanging

Question:

A vertical, 1.20-m length of 18-gauge (diameter of 1.024 mm) copper wire has a l00.0-N ball hanging from it
(a) What is the wavelength of the third harmonic for this wire?
(b) A 500.0-N ball now replaces the original ball. What is the change in the wavelength of the third harmonic caused by replacing the light ball with the heavy one? (Hint: See Table 11.l for Young's modulus.)