Chapter 12, Problem 1P

To determine

The length of the lake by listening for the echo.

Answer to Problem 1P

Solution:

The length of the lake will be $425.36m$

Explanation of Solution

Given:

Echo 2.5s

Assuming the lake is at sea level.

The speed of the sound is$=340.29m/s$

Therefore

$\text{Echo}\text{x}\text{speed of the sound}$

$2.5\times 340.29=850.725min2.5\text{}s$

Divide in half to account for travel to and from the cliff

$\frac{850.725}{2}=425.36m$