(a) Away from the normal
The direction of bending of the ray of light can be found by using Snell's law:
where
n1, n2 are the index of refraction of the first and second medium, respectively
are the angle of the incident and refracted ray with respect to the normal to the surface, respectively
In this problem, the ray of light moves from a material with high index of refraction to a material with lower index, so:
Re-arranging Snell's law we find
since
we also have
so the ray of light bends away from the normal.
(b) The wavelength is greater in the second material (the one with lower index of refraction)
The wavelength of the light in a medium is given by
where
is the wavelength of the light in a vacuum
n is the refractive index
We can rewrite the equation as
And isolating from the second equation
where
So, we have that the wavelength in the second medium (the one with lower index of refraction) is longer than the wavelength in the first medium.
(c) The frequency is the same
While wavelength and speed of a light wave depend on the medium in which the wave is travelling through, the frequency does not depend on that, so it is exactly the same in the two mediums.