Waves (Physics)

Recall cards on traveling and standing waves. Mechanical waves in a medium versus electromagnetic and matter waves. Amplitude, wavelength, period, and frequency, and the wave-speed relations v = lambda/T = lambda*f. Transverse versus longitudinal (compressional) waves. The mathematics of waves: the sinusoidal wave function y = A sin(kx - omega t + phi), wave number k = 2 pi/lambda, angular frequency omega = 2 pi/T, the phase and phase constant, transverse velocity and acceleration of a medium element, and the linear wave equation. Wave speed on a stretched string v = sqrt(F_T/mu) and the general elastic-over-inertial form. Energy and power of a wave: P = (1/2) mu A^2 omega^2 v, the amplitude-squared and frequency-squared scaling, intensity I = P/A, and the inverse-square law for a point source. Interference and superposition: constructive and destructive interference and the resultant amplitude 2A cos(phi/2). Standing waves and resonance: nodes and antinodes, the standing-wave function y = 2A sin(kx) cos(omega t), allowed wavelengths lambda_n = 2L/n and resonant frequencies f_n = n f_1 on a string fixed at both ends, harmonics, overtones, normal modes, and resonance.