What is the angle of this light ray when it enters the water?
An aquarium filled with water has flat glass sides whose index of refraction is 1.56. A beam of light from outside the aquarium strikes the glass at a 43.5 (degree) angle to the perpendicular .
the angle of this light ray when it enters the glass= 26.2degrees
Questions: What is the angle of the light ray when it enters the waterÉ
What would be the refracted angle if the ray entered the water directly?
air-glass boundary>
a[u]g = ug/ua = sin 43.5/sin26.2
ua = ref index of air (or vacuum) = 1
ug = 1.559 = 1.56 (as given)
———————————————- glass-water
g[u]w = uw/ug = sin 26.2/sin (w)
uw = 4/3 = 1.333
sin (w) = [1.56/1.333] sin 26.2
sin (w) = [1.56/1.333] sin 26.2 = 0.5167
w = sin^-1[0.5167]
w = angle in water = 31.111 degree
============================
if light entered directly
uw/ua = sin 43.5/sin(w) = 1.333/1
sin(w) = 0.5164
w = 31.1 degree