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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 w 2 = k/m w = (2 p rad / 1 rev) f x(t) = A cos( w t+ f ) E = ½ k x 2 + ½ m v 2
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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 w2 = k/m w = (2p rad / 1 rev) f x(t) = A cos(wt+f) E = ½ k x2 + ½ m v2 Pendulum w2 = g/L Physical, torsional pendulum Damped oscillations
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 w2 = k/m w = (2p rad / 1 rev) f x(t) = A cos(wt+f) E = ½ k x2 + ½ m v2 Pendulum w2 = g/L Physical, torsional pendulum Damped oscillations
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
An angular frequency of 10 rad/s corresponds to an “ordinary” frequency (in Hz or cycles/sec) of • 1.59 • 0.1 Hz
PH 105-003/4 ---- Wednesday, Nov. 12, 2007 Chapter 16: Waves F=ma wave equation y(x,t) = f(x-vt) where v2 = T/m Sinusoidal waves: y(x,t) = A sin(kx – wt) where k=2p/l, (& w = 2p/T as for SHM) Chapter 17: Standing waves: A sin(kx) cos(wt)