Question

A marine survey ship sends a sound wave straight to the sea bed. It detects an echo 4.0 s later. What is the approximate depth of the sea?

• A. 600 m
• B. 1500 m
• C. 3000 m
• D. 10000 m

Answer 1

The correct option is C

3000 m

Speed of sound in water = 1484 m/s Time taken by sound to reach the bottom of the sea $=\frac{\text{(time lapse in detection of echo)}}{2}=\left(\frac{4}{2}\right)s=2s$.

Depth of sea = 1484 m/s $\times$ 2 s = 3000m (approx).