Two sources of sound are emitting progressive waves y₁=4 710 t and y₂=3 702 t . The sources are placed close to each other. The number of beats heard per second and intensity ratio between waxing and waning are respectively

Step-by-step solution

The progressive waves are given as y₁ = 4 710 t and y₂ = 3 702 t . From the standard wave form y = A t , the amplitudes are A₁ = 4 and A₂ = 3 , with angular frequencies ₁ = 710 rad/s and ₂ = 702 rad/s. The beat frequency is the difference in the individual frequencies. Since f = 2 , f₁ = 355 Hz and f₂ = 351 Hz, so f_ beat = |355 - 351| = 4 beats/s. Under constructive and destructive interference, the maximum and minimum amplitudes are A_ max = A₁ + A₂ = 7 and A_ min = |A₁ - A₂| = 1 . Since intensity I A^2 , the rat