Questions 5 and 6 refer to a beam of
light that passes through a sheet of plastic and out into the air.
The angle the beam of light makes with the normal as it passes through
the plastic is , and the angle the beam of light
makes with the normal as it passes into the air is . The index of refraction for air
is 1 and the index of refraction for plastic is 2.


5. 
What is
the value of sin, in terms of ? 
 (A) 
sin 
 (B) 
2 sin 
 (C) 
sin 2 
 (D) 
sin 
 (E) 
4 sin 


6. 
What is
the minimum incident angle for which the light will undergo total
internal reflection in the plastic? 
 (A) 
sin^{–1 } 
 (B) 
sin^{–1} 
 (C) 
sin^{–1} 2 
 (D) 
0Âº 
 (E) 
90Âº 
