If light enters a medium with an angle of incidence of 23 degrees and has an angle of refraction of 18 degrees, what is the refractive index of the medium?

An equation for calculating the refractive index of a substance is ...

The velocity of light in vacuum is _______ ms(-1)

Light passing from air to glass will cause the light to

A light ray hits a plane surface at 20 °C. What is the angle between the incident and reflected rays. 

Swimming pools and the ocean look shallower than they really are due to: