PHYSICS 8A Lecture Notes - Lecture 1: Thermodynamic Cycle, Carnot Cycle, Ideal Gas
Document Summary
X(t) = acos( t) or more generically x(t) = acos( t + ) , comes from m d2x dt2. E = u + k = mv 2 + kx 2. For simple pendulums (assume point mass where i = ml 2 ), use = distance between the pivot point and center of mass g. T v = = f y(x) = acos( x) Wave number k k = . Interference y(x,t) = acos(kx t) sinusoidal wave k. Superposition principle waves whose displacements simply add. Constructive interference two waves superposing to produce a larger wave displacement. Destructive interference the two waves cancel. Beats interference of two nearly equal frequencies produces intensity y(t) = acos 1 t+acos 2 t cos + cos = 2cos[ ( - ) ]cos[ ( + )] y(t) = 2acos[ ( 1 - 2 )t ]cos[ (( 1 + 2 )t)] variations. The closer the 2 frequencies, the longer the period between beats.
