Tuning an Instrument. A musician tunes the C-string of her instrument to a fundamental frequency of 65.4

Question:

Tuning an Instrument. A musician tunes the C-string of her instrument to a fundamental frequency of 65.4 Hz. The vibrating portion of the string is 0.600 m long and has a mass of 14.4 g.
(a) With what tension must the musician stretch it?
(b) What percent increase in tension is needed to increase the frequency from 65.4 Hz to 73.4 Hz, corresponding to a rise in pitch from C to D?