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Physics help, thank you! ?
A point source of light is submerged 2.3 m below the surface of a lake and emits rays in all directions. On the surface of the lake, directly above the source, the area illuminated is a circle. What is the maximum radius that this circle could have? Take the refraction index of water to be 1.333.
1 Answer
- ?Lv 72 weeks agoFavorite Answer
The maximum radius corresponds to the critical angle --
Θcrit = arcsin(n_air / n_water) = arcsin(1.000/1.333) = 48.6º
then tan(Θcrit) = R/d means that
R = d*tan(Θcrit) = 2.3m * tan48.6º = 2.6 m
