• A student has a small battery-powered alarm buzzer. The student throws the buzzer toward a stationary wall (possibly due to frustration). The buzzer emits sound with a frequency of 92 Hz and the wall reflects the sound. If the buzzer is moving directly away from the student (and directly toward the wall) with a speed of 6.3 m/s, what beat frequency would the student hear?
• The speed of sound is 340 m/s. The student stands still after throwing the buzzer.