Select all that apply light travels in longitudinal waves does not require a medium to travel through slows down when traveling through more dense substances speeds up when traveling through less dense substances can be absorbed and transformed into heat is refracted when it changes direction and speed need !

Light travels in longitudinal wave and is refracted when it changes direction and speed.

Explanation:

First, refraction is defined as the change in direction of light as it passes through one medium to another. This means that light rays changes direction as well as speed when refracted i.e when passing through a pair of media. Before light can be refracted, it must have pass from one medium to another.

Also, light travels longitudinally that is the direction of the light is parallel to the direction of the wave produced by the light. One of the properties of wave that proves this is polarization. In polarization, light is made through pass through a tiny hole known as slit.