# Physics H133: Problem Set #1

Here are some hints, suggestions, and comments on the problem set.

## Two-Minute Problems

Remember to give a good explanation, no longer than two sentences.

1. Q1T.11: Will a string strongly resonate (absorb energy) from a disturbance at any frequency at all?
2. Q1S.1: What property of the instrument does the pitch depend on? (What property of a pipe does the fundamental pitch depend on?) Note: the pitch is the same as the frequency.

## Chapter Q1 Problems

• Q1B.1: Just like exercise Q1X.1. Be careful of signs, however.
• Q1B.7: Draw pictures for the lowest normal modes to pick out the one with three anti-nodes. Count half wavelengths!
• Q1S.7: What are the boundary conditions for one end open and one end closed? Figure out where the nodes are in terms of fractions of a wavelength.
• Q1S.10: Follow the handout on dimensional analysis.
• Q1A.1: How are theta, dL, and R related for a circular arc? (Example: if theta=2*pi, dL is the circumfrence = 2*pi*R.) If you know the mass per length mu, what is the mass m of the bit of string of length dL?
• Q1R.1: What does "the pulse is inverted" mean for a sound wave? Remember that the quantity changing for a sound wave is the difference from the ambient density (or pressure).