Chapter 26, Problem 47A

On a field trip to Echo Cave, you clap your hands and receive an echo 1 second later. How far away is the cave wall?

To determine

The distance of the cave wall when you clap your hands in an echo cave and receive an echo 1 s later.

Answer to Problem 47A

The distance of the cave wall is 170 m when you clap your hands in an echo cave and receive an echo 1 s later.

Explanation of Solution

Given:

Speed of sound wave ( $\mathrm{s}$ ) = $340m{s}^{-1}$

Time taken by sound wave (echo) to travel to the cave wall and reflect back = 1 s

So,

Time taken by sound wave to travel to the wall ( $\mathrm{t}$ ) only = $\frac{1s}{2}=0.5s$

Formula used:

Distance of the cave wall ( $\mathrm{d}$ ) = $\mathrm{speed}ofsoundwave(s)\times time(t)$

Calculation:

Putting the values and we get;

Distance of the cave wall ( $\mathrm{d}$ ) = $340m{s}^{-1}\times 0.5s=170m$

Conclusion:

The distance of the cave wall is 170 m when you clap your hands in an echo cave and receive an echo 1 s later.