CAPE Physics Unit 1 · 2016 · Paper 1 · Question Q20

A ship sends down a pulse of sound to measure the depth of the sea. The echo is detected 0.1\text{ s} later. Assuming that sound waves travel five times faster in seawater than in the air, how deep is the sea at this point? (Speed of sound in air = 330\text{ m s}^{-1})

1. (A)25\text{ m}
2. (B)83\text{ m}
3. (C)248\text{ m}
4. (D)1650\text{ m}