Solve Light Refraction Homework: Angle of Sunlight in Water

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To solve the homework problem regarding the angle of sunlight entering water, the relevant equation is n1sin(theta1) = n2sin(theta2), where n1 is the index of refraction for air and n2 for water. The swimmer observes the sunlight at an angle of 18.7° with the vertical, which indicates that this angle is measured after the light has entered the water. The correct approach involves recognizing that this angle does not directly correspond to the angle of incidence above the water's surface. The mistake was initially using the 18.7° angle as the angle of incidence instead of converting it appropriately. Understanding the context of the angle measurement is crucial for finding the correct solution.
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Homework Statement


An underwater swimmer observes that a beam of sunlight in the water makes an angle of 18.7° with the vertical. The index of refraction for water is equal to 1.33. Assuming the surface of the water is level, determine the beam's angle as it enters the water.


Homework Equations



n1sin(theta1)=n2sin(theta2)


The Attempt at a Solution



I tried using different angles but I can't seem to get the correct answer. At first I used 18.7 degrees and found that to be incorrect. Than I thought that 18.7 might not correspond since it is made with the vertical and not the horizontal, so I used 90-18.7= 71.3 degrees but that didnt work either. I am not sure if I am using the wrong equation or if I am misreading the question.
 
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Nevermind I found my mistake. I didn't realize the 18.7 degree angle was after it already was in the water. Thanks anyway.
 
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