Problem 4. A string of length 2m with both ends fixed is plucked by some curious students. The observe two different standing waves, the first with 6 nodes, and the second with 4 nodes. The frequency of the first is 150H z higher than the second. a) Which harmonics are the two standing waves? b) What is the wavelength of the first harmonic? c) What is the speed of the waves on the string? d) What is the frequency of the harmonic between the two you created?e) You want to use this string as part of a musical instrument. What frequency would you hear from the fundamental produced on this string? f) If one of the ends is made free rather than fixed, what is the frequency of the first harmonic