Two sound waves have frequencies of 250 Hz and 280 Hz. What beat frequency do they produce when superimposed?

1. Identify the knowns: f1 = 250 Hz and f2 = 280 Hz. 2. Use f_B = |f1 - f2|. 3. Substitute: f_B = |250 Hz - 280 Hz| = 30 Hz, matching option D. 4. Option A, 290 Hz, instead adds the two frequencies together rather than subtracting them. _Source: OpenStax Physics (CC BY 4.0), Ch 14 "Sound", section Resonance and Beats_