Answer:
option A
Explanation:
given,
diameter of circle = 10 ft
refractive index of the water = n = 1.33
let the inclined surface of the cone makes an angle θ with vertical line then
[tex]tan \theta = \dfrac{radius\ of\ circle}{verticle\ length}[/tex]
[tex]h= \dfrac{radius}{tan\theta }[/tex]
we know,
[tex]sin \theta = \dfrac{1}{n}[/tex]
[tex]sin \theta = \dfrac{1}{1.33}[/tex]
[tex]\theta =sin^{-1}(\dfrac{1}{1.33})[/tex]
from this θ = 48.75°
substitute this in eq ( 1 ) we have
[tex]h= \dfrac{5}{tan 48.75}[/tex]
h = 4.38
h = 4.4 (approx.)
Hence, the correct answer is option A
