Question Detail
Question
Two sound waves are described by y₁ = yₘ sin(ω₁t) and y₂ = yₘ sin(ω₂t). According to the document, when these waves superimpose, what is the beat frequency observed?
Correct Answer
Option B is the correct answer.
Detailed Explanation
On page 16, under 'Beats' and 'Doppler Effect', the document explicitly states: 'Each of these [maxima in amplitude] occurs once in a cycle, and thus, the beat frequency is twice fenv, or equal to f₂ - f₁.' Where fenv = (f₂-f₁)/2. So, beat frequency = 2 * fenv = 2 * (|f₂-f₁|/2) = |f₂-f₁|.
Hint
Refer to the 'Beats' section on page 15-16, specifically the definition of beat frequency.