A diver looking up through the water sees the outside world contained in a circular…

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

A diver looking up through the water sees the outside world contained in a circular horizon. The refractive index of water is

\frac{4}{3}

, and the diver's eyes are 15 cm below the surface of water. Then the radius of the circle is: (1)

15 \times 3 \times \sqrt{5} \text{ cm}

(2)

15 \times 3 \times \sqrt{7} \text{ cm}

(3)

\frac{15 \times \sqrt{7}}{3} \text{ cm}

(4)

\frac{15 \times 3}{\sqrt{7}} \text{ cm}