Emma draws a sketch of what happens to light as it moves through air and then into a tank of water. describe what happens to the speed of light as it enter the water. Answer if you know, if you don't move on please! If you don't know comment not answer. Thank you!!

The speed of light becomes slower in denser medium which is water in this case.

Explanation:

We know the lens law of Refraction which states

 Refractive index of second medium /Refractive index of the first     medium

= Velocity of light in medium 1 (V1)/ velocity of light in medium 2 (V2)

When light rays fall from air medium into water which is a denser medium bending of light or change in the direction of light occurs which is knows as Refraction.

When refraction occurs speed of the light rays are also varied as we can see it from the Lenz's Law. suppose two light rays parallel to each other falling on the air-water interface at an angle , the first ray will reach the interface and bend about the normal and then the second ray. We also observe when light enters denser medium the speed of light becomes slower, also the bending of light when going from rarer to denser it bends towards normal of the surface and when it move from denser to rarer medium it moves away from the normal to the surface.