Which statements are correct for a plane sinusoidal sound wave of pressure amplitude Δpₘ and particle-displacement amplitude sₘ?
Select all that apply

Question

Which statements are correct for a plane sinusoidal sound wave of pressure amplitude Δpₘ and particle-displacement amplitude sₘ?

G1 Physics · Accepted Answer

The average intensity is I = ½ρ₀vω²sₘ². Since Δpₘ = ρ₀vωsₘ, substitution gives I = Δpₘ²/(2ρ₀v). Thus intensity is proportional to pressure-amplitude squared. For a surface normal to propagation, P̄ = IA. Therefore all four statements are correct.