Answer: 48.6 degrees (critical angle cone).
- A 90 degrees, as if light entered the water with no bending at all
- B 48.6 degrees (critical angle cone)
- C 45 degrees, a value unrelated to the actual critical angle of water
- D 60 degrees, a value unrelated to the actual critical angle of water
Correct answer: B. 48.6 degrees (critical angle cone)
Explanation: Fish sees the entire above-water world compressed into a cone of half-angle = critical angle = sin<sup>-1</sup>(1/1.33) = 48.6 degrees.
Concave mirror ray construction: a ray parallel to the axis reflects through F, and a ray through F reflects parallel, locating the inverted real image. Image: Maxmath12, CC0, via Wikimedia Commons.
Concept context
Reflection, refraction, lenses, mirrors, total internal reflection.