Reflection & Refraction A light ray enters a rectangular block of plastic $(n=1\mathrm{.}2)$ at an angle ${}_1=50\mathrm{.}0$ as shown in the figure below

$($a$)$ Determine the angle of the outgoing ray with the normal at the air$-$plastic interface

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$($b$)$ Determine the angle of the incident ray with the normal at the point where the ray exits the block of

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plastic

$($c$)$ Determine the angle ${}_2$ of the outgoing ray with the normal at the exit point $($if you did not solve $($b$)$ assume the incoming angle with the normal is $25)$

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$($d$)$ Determine the angle of total internal reflection at the exit point

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$($e$)$ The block of plastic is now immersed in a liquid with index of refraction $n_1.$ At what value of $n_1$ is the ray totally internally reflected at point P$?$ Assume the incoming angle does not change. $($if you did not solve $($b$)$ assume the incoming angle with the normal is $25)$

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$($f$)$ What is the angle of the outgoing ray with respect to the normal assuming it is totally internally reflected?

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