A plane wave of sound travelling in air is incident upon a plane water surface. The angle of incidence is `60^@`. Assuming snell's law to be valid for sound waves, it follows that the sound wave will be refracted into water away from the normal.

Explanation

To solve the problem of a plane wave of sound traveling in air incident upon a plane water surface at an angle of incidence of \(60^\circ\), we will apply Snell's Law, which states:

\[ \frac{\sin \theta_1}{\sin \theta_2} = \frac{v_1}{v_2} \]

where:
- \(\theta_1\) is the angle of incidence (in air),
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