alleryStart learning →A singer's note makes a piano string sound without touching it. What is happening?
AThe string is being damped
BThe string is refracting the note
CThe string is resonating with the note
DThe string is reflecting the note
Answer & Solution
Correct answer: C. The string is resonating with the note
1. Sing into a piano with the sustain pedal down and it sings the same note back.
2. The strings sharing the frequency of the voice resonate in response to the sound waves.
3. That is resonance: driving a system at its own natural frequency.
4. Damping is the opposite process, in which the oscillation dies away.
_Source: OpenStax Physics (high school, CC BY 4.0), Ch 14 "Sound", section Resonance and Beats_
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