Answer:
48.9°, 29°
Explanation:
We kno that snell's law States that
( sin i / sin r ) = ( n 2 / n 1 )
And here
i = 90 - α
r = 90
n 2 = n a = 1.00029
n 1 = n = 1.52
So
( sin ( 90 - α ) / sin 90 ) = (1.00029 / 1.52 )
= 0.658
sin ( 90 - α ) = 0.658
90 - α = sin -1 ( 0.658 )
= 41.15
α = 90 - 41.15
= 48.9°
( b ) to find angle when prism immerssed in water
Using snell's law again
( sin i / sin r ) = ( n 2 / n 1 )
here i = 90 - α
r = 90
n 2 = n w = 1.33
n 1 = n = 1.52
So
( sin ( 90 - α ) / sin 90 ) = (1.33 / 1.52 )
= 0.875
sin ( 90 - α ) = 0.875
90 - α = sin -1 ( 0.875 )
= 61
α = 90 - 61
= 29°