Respuesta :
Given:
The depth of the trench, d=10,918 m
The refractive index of the water, n=1.33
To find:
The time it takes for the laser beam to reach the bottom of the ocean.
Explanation:
The refractive index of water is given by,
[tex]n=\frac{c}{v}[/tex]Where c is the velocity of the laser in vacuum and v is the velocity of the laser in water.
On substituting the known values,
[tex]\begin{gathered} 1.33=\frac{3\times10^8}{v} \\ \implies v=\frac{3\times10^8}{1.33} \\ =2.3\times10^9\text{ m/s} \end{gathered}[/tex]The velocity is given by the equation,
[tex]v=\frac{d}{t}[/tex]Where t is the time it takes for the laser to reach the bottom of the trench.
On substituting the known values,
[tex]\begin{gathered} 2.3\times10^8=\frac{10,918}{t} \\ \implies t=\frac{10,918}{2.3\times10^8} \\ =47.5\times10^{-6}\text{ s} \\ =47.5\text{ }\mu\text{s} \end{gathered}[/tex]Final answer:
The laser beam would reach the bottom in 47.5 μs
