A boy shouts down into a deep, dry well and hears his echo $0.4\text{ seconds}$ later. If the speed of sound…
A boy shouts down into a deep, dry well and hears his echo $0.4\text{ seconds}$ later. If the speed of sound in air is $340\text{ m/s}$, how deep is the well?
$136\text{ meters}$
$68\text{ meters}$
$34\text{ meters}$
$17\text{ meters}$
Solution
Total distance traveled by sound = $340 \times 0.4 = 136\text{ meters}$. Depth of the well = $136 / 2 = 68\text{ meters}$.