1. (10 pts) Piano tuners tune pianos by listening to the beats between the harmonics of two different strings. When properly tuned, the note A should have a frequency of 440 Hz and the note E should be at 659 Hz. a. What is the frequency difference between the third harmonic of the A and the second harmonic of the E? b. A tuner first tunes the A string very precisely by matching it to a 440 Hz tuning fork. She then strikes the A and E strings simultaneously and listens for beats between the harmonics. What beat frequency indicates that the E string is properly tuned? C. The tuner starts with the tension in the E string a little low, then tightens it. What is the frequency of the E string when she hears four beats per second? For each part of the problem, follow Problem solving steps to show in your solutions listed under the instructions for Work-Out Problems. a (b) (c) (d) (e) ( f) 2. (10 pts) The figure shows a thin rod of length _ with total charge D a. Find an expression for the electric field strength on the axis of the rod at distance / from the center Express your answer in terms of the variables _. Q -, and appropriate constants. b Verify that your expression has the expected belist ist its 5 / Express your answer in terms of variables O., and constants . c. Evaluate Eater - 34 cm it. 50 em and 2 25