1. A.PH 105-003/4 ----Monday, Nov. 12, 2007 Homework: PS 11 (Ch. 11, due last week – review #5) PS 12, Chapter 14, is due Nov 14. Chapter 15: Oscillations (review) Mass on spring: F = -k x   2 = k/m  = (2  rad / 1 rev) f x(t) = A cos(  t+  ) E = ½ k x 2 + ½ m v 2 Pendulum  2 = g/L Physical, torsional pendulum Damped oscillations

2. A.PH 105-003/4 ----Wednesday, Nov. 14, 2007 Homework: PS 12, Chapter 14, is due tonight Chapter 15: Oscillations (review) Mass on spring: F = -k x   2 = k/m  = (2  rad / 1 rev) f x(t) = A cos(  t+  ) E = ½ k x 2 + ½ m v 2 Pendulum  2 = g/L Physical, torsional pendulum Damped oscillations

3. Clicker question: A mass m = 0.1 kg oscillates on the end of a spring with spring constant k = 10 N/m. The oscillation frequency (angular, in rad/s) is 10 0.5

4. An angular frequency of 10 rad/s corresponds to an “ordinary” frequency (in Hz or cycles/sec) of 1.59 0.1 Hz

5. Chapter 16: Waves F=ma  wave equation  y(x,t) = f(x-vt) where v 2 = T/  Sinusoidal waves: y(x,t) = A sin(kx –  t) where k=2  /  &  2  /T as for SHM) Chapter 17: Standing waves: A sin(kx) cos(  t) A.PH 105-003/4 ---- Wednesday, Nov. 12, 2007