handin06

# handin06 - Physics 212 Classical and Modern Physics Spring...

This preview shows pages 1–2. Sign up to view the full content.

Physics 212 Classical and Modern Physics Spring 2008 Solutions for Hand-In Set #6 Problem A35 — Annoying your roommate (a) The whistle has an opening near the mouthpiece, so that end of the tube is an anti-node for the dis- placement of air. The end where the plunger is makes a node, so we’re looking for node/anti-node end con- ditions. Playing the whistle softly gives the longest wavelength mode: L (b) Blowing harder switches from the fundamental ( n = 1) to the first harmonic ( n = 2), which looks like this: L In the first case, there was one-quarter of a wavelength, so 1 4 λ 1 = L λ 1 = 4 L Now we have three-quarters of a wavelength, so 3 4 λ 2 = L λ 2 = 4 3 L Since the wavelength decreased by a factor of three, the frequency f = v/λ increased by a factor of three. (c) Blowing harder until it squawks unpleasantly gets us to the n = 3 mode: L Here we have a full wavelength and a quarter, so 5 4 λ 2 = L λ 2 = 4 5 L This is one-fifth the wavelength in part (a), so the fre- quency is five times the fundamental. Problem A37 — Stringed instruments (a) The three longest standing wave patterns are illus- trated in the figure. L n =1 n =2 n =3 (b) For the n = 1 mode, λ 1 = 2 L = 2 × 1 . 2 m = 2 . 4 m. The wavenumber is k 1 = 2 π λ 1 = 2 π 2 . 4 m = 2 . 62 m - 1 .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern