A student stands $170\text{ m}$ away from a large brick wall. She claps two wooden blocks together repeatedly at a steady rate so that each clap coincides exactly with the echo of the previous clap. If she counts $20$ claps in $20.0\text{ s}$, what is her experimental value for the speed of sound in air?

• A$170\text{ m/s}$
• B$340\text{ m/s}$
• C$680\text{ m/s}$
• D$1360\text{ m/s}$

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