A ray in plastic has a critical angle of 44.4 deg when trying to enter air. What is the index of refraction for the plastic?

1.43

Explanation:

Given that:

C (critical angle) = 44.4°

n (refractive index of plastic) = ?

Apply the formula n = 1/sineC, the index of refraction for the plastic can be obtained by:

n = 1/sineC

n = 1/sine 44.4°

n = (1/0.6996)

n = 1.43

Thus, the index of refraction for the plastic is 1.43