A beam of white light goes from air into water at an incident angle of 84.0∘. At what angles are the red 660 nm and violet 410 nm parts of the light refracted? Red light in water has an index of refraction equal to 1.331 and that of violet light is 1.342.

Red light has an angle of refraction of 48.3°.

Violet light has an angle of refraction of 47.8°.

Explanation:

From Snell's law of refraction, the refractive index is the ratio of the sine of the angle of incidence to the sine of the angle of refraction.

For red light in water,

For violet light in water,

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.