Wednesday, June
1, 2011
Announcements:
- Solutions to the Flywheel problem for Exam 2 are due
this morning.
- The multiple-choice section of Exam 2 will be tomorrow
during our regular class time. If
you want to take this exam early (today), please let me know.
- Remember to bring at
least one Scantron answer sheet, a scientific
calculator, and a #2 pencil.
Assignments:
Chapter
13 - Oscillations and Simple Harmonic Motion
Period T is the time for a motion
to repeat.
Frequency is the number of oscillations or cycles per unit of time:
f = 1/T
Angular frequency: w = 2pi*f
Simple Harmonic Motion (SHM) is a special kind of periodic motion where
the restoring force is proportional to the displacement from equilibrium.
Amplitude is the maximum displacement from equilibrium (when v = 0).
Mass on a spring
Simple pendulum
Damped oscillations
Resonance
Ponderables:
- Examples and applications of SHM: rocking chair,
vibrating vocal chords, NMR, blue sky, drug testing...
- If the length of a pendulum is doubled, what happens to
its period of oscillation?
- How does the frequency of oscillation of a pendulum
depend on amplitude? What about damping?
- Would the period of a pendulum increase, decrease, or
stay the same in a vacuum?
- A simple pendulum exhibits SHM for small angles.
At what angle is the error in the period larger than 1%?
- How is a physical pendulum different from a simple
pendulum?
- What happens to the period of a mass-spring system if
the mass is doubled?
- What happens to the period if the spring is cut in
half?
- Why are car radio antennas about 0.75 m long?
Demos
- Simple pendulum - T, L, g
- Mass-spring system - T, k, m
- Vibrating string - v, f, lamda,
tension, L, harmonics, mu
- Resonance rods