## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (3rd Edition)

Published by Pearson

# Chapter 20 - Traveling Waves - Exercises and Problems - Page 588: 46

#### Answer

They will have to drill 800 meters into the granite.

#### Work Step by Step

We can find the time $t_w$ for the sound wave to travel through 1000 meters of water (down and back up). $t_w = \frac{d_w}{v_w}$ $t_w = \frac{1000~m}{1500~m/s}$ $t_w = 0.67~s$ We can find the time $t_g$ the sound wave spent traveling in the granite. $t_g = t - t_w$ $t_g = 0.94~s - 0.67~s$ $t_g = 0.27~s$ We can find the total distance the sound wave traveled through granite (down and back up). $d_g = v_g~t_g$ $d_g = (5950~m/s)(0.27~s)$ $d_g = 1600~m$ Since the thickness of the granite is half the total distance, they will have to drill 800 meters into the granite.

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.