How to Solve for the Angle of Refraction From Water to Air
- 1). Compute the sine of the angle of incidence for the light striking the air from inside the water. For example, if the angle of incidence is 30 degrees, then the sine of 30 degrees equals 0.5.
- 2). Multiply the sine of the incident angle by the index of refraction for water. Divide by the index of refraction for air. Call this result "X." The indexes of refraction for water and air equal 1.33 and 1.000227 respectively. Continuing the example, you have 0.5 times 1.33 divided by 1.000227, or 0.66 for "X."
- 3). Take the inverse sine of "X" to arrive at the angle of refraction in the air in degrees. The inverse sine key on a calculator is denoted by a "SIN" with an exponent of minus one. Completing the example, taking the inverse sine of 0.66 yields an angle of refraction of 41.30 degrees.
