Home > SparkNotes > Physics Study Guides > Light >

sparknotes

Light


Problems on Light as a wave

Problem : Find an expression for the angular frequency of a wave in terms of the wavelength and phase velocity.


Problem : If the numbers in this problem are given in SI units, calculate the velocity of a wave given by the equation: ψ(y, t) = (9.3×104)sin[Π(9.7×106 y + 1.2×1015 t)] .


Problem : Write the equation for a wave with an amplitude 2.5×103 V/m, a period 4.4×10-15 seconds, and speed 3.0×108 m/s, which is propagating in the negative z -direction with value 2.5×103 V/m at t = 0 , z = 0 .


Problem : Consider the wave ψ(x, t) = A cos(k(x + vt) + Π) . Find an expression (in terms of A) for the magnitude of the wave when x = 0 , t = T/2 , and x = 0 , t = 3T/4 .


Problem : Demonstrate explicitly that a harmonic function ψ(x, t) = A cos(kx - σt) satisfies the wave equation. What condition needs to be fulfilled?