An incident light ray strikes water at an angle of 20 degrees. The index of refraction of air is 1.0003, and the index of refraction of water is 1.33. The angle of refraction rounded to the nearest whole number is °.

In order to find the angle of the refracted ray, we may use the Snell's law (also known as Snell-Descartes law and the law of refraction). This law states that the ratio of the sines of the angles of incidence and refraction is constant for a given wave when it passes through two different media such as water, glass, or air.

In mathematical form, this is:

n₁sin (∅₁) = n₂sin (∅₂)

Where:n is the refractive index.

Plugging in the values given into the equation:

1.0003 * sin (20°) = 1.33 * sin (∅)

∅ = 14.91

The angle of refraction is 15°.