P6: REFLECTION AND REFRACTION Flashcards
What is the law of reflection?
angle of incidence = angle of reflection
What is the angle of incidence?
angle between incoming wave and normal
What is the angle of reflection?
angle between reflected wave and normal
What is the normal?
an imaginary line perpendicular to the surface at the point of incidence
What is specular reflection?
when a wave is reflected in a single direction by a smooth surface
What is diffuse reflection?
when a wave is reflected by a rough surface and the reflected rays are scattered in many different directions
RP - Reflection: method
-draw a straight line across a piece of paper and place a mirror so one of its sides lines up with the line
-shine a ray of light at the object’s surface and trace the incoming and reflected light beams
-draw the normal at the point where the ray hits the object
use a protractor to measure the angle of incidence and the angle of reflection
Why do light waves refract when they pass from air into glass?
-light waves travel slower in glass than in the air
-because glass is more dense
If the boundary is more dense, do light rays bend towards/away from the normal?
towards normal
RP - Refraction: method
-place a transparent rectangular 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 mark where the light ray emerges on the other side of the block
-remove block and join up the incident ray and the emerging point (with a straight line) to show the path of the refracted ray through the block
-draw the normal at the point where the light ray entered the block
-use a protractor to measure the angle between the incident ray and the normal (angle of incidence) and the angle between the refracted ray and the normal (angle of refraction)
