Refraction Flashcards
what is refraction
when light waves go through a transparent object and leave at a different angle
if light is coming in from a less dense object to a denser object, how does it react
it refracts towards the normal due to the decrease in velocity
if light is coming in from a denser object to a less dense object, how does it react
it refracts away from the normal due to the increase in velocity
the denser the material…
the closer to the normal the light refracts to
what is the ‘normal’ in refraction
the angle perpendicular to the side of the object the light is entering from
effects of refraction in our daily lives and why
- swimming pools look shallower than they are
- this is because light from the bottom of the pool bends when it comes out of the surface
what is transmission
when all light waves move through an object without being absorbed
describe an experiment where you can investigate refraction
- place a rectangular glass block on a piece of paper and trace around it
- use a ray box to shine a ray of light at the middle of one side of the block
- trace the incident ray and the emergent ray on the other side of the block
- remove the block and join up the incident and emergent ray with a straight line
- showing the path of the refracted ray through the block
- draw the normal at the point where the ray entered the block and do the same for the emergent ray
what is the angle of the incidence in the experiment
the angle between the incident ray coming in and the normal
what is the angle of emergence in the experiment
the angle between the emergent ray coming out and the normal
what would you see from the experiment for refraction
- the ray of the light bends towards the normal as it enters the block
- so the angle of refraction is less than the angle of incidence
why is the angle of refraction less than the angle of incidence in the refraction experiment
- air has one of the lowest optical densities that there is
- so the light ray will slow down when it enters the block
why is the angle of refraction less than the angle of emergence in the refraction experiment
the light ray speeds up as it leaves the block and travels through the air