Answer:
radius is 3.197 m
Explanation:
Given data
index of refraction = 1.35
submerged h = 2.90 m
to find out
radius of the circle
solution
we know here that light will be escape only if angle of critical is less than angle of incidence
so we can say
sin (θ)i = 1 / index of refraction
here angle (θ)i is critical angle so
sin (θ)i = 1 / 1.35 = 0.7407
(θ)i = 47.79 degree
we consider here radius r of circle
so
tan (θ)i = R /h
so
R = 2.90 tan ( 47.79)
R = 3.197 m
so radius is 3.197 m