Light, Reflection And Refraction Flashcards
Specular
Reflection from a smooth surface (one direction)
Diffuse
Reflection from a rough surface (many reflection)
Refraction air to glass
Ray refracts towards the normal as light travels slower in glass than air
Sunglasses
Absorb more UV rays
Colour
Depends on which wavelengths are reflected and which are absorbed
Transparent
Allows all light to pass through and we can see through clearly
Translucent
Allows light to pass through but we can’t see through clearly
Opaque
Doesn’t allow light to pass through, light will be reflected or absorbed, determining colour
Reflection practical
1) use a stand to place a mirror upright on a sheet of paper
2) direct ray from ray box to the mirror
3) draw up the incident and reflected rays
4) draw normal and use protractor to measure the angle of incidence and angle of reflection
Law of reflection
Angle of incidence = angle of reflection
If the angle of incidence is smaller than the critical angle…
/
If the angle of incidence is larger than the critical angle…
/\ (total internal reflection)
If the angle of incidence is equal to the critical angle…
__
/
Convex (converging) lens
1) draw a line from the top of the object to the centre of the lens
2) continue this line to cross through the right F
3) draw a line from the top of the object down to the centre
4) either connect up these rays or draw another lien through the left F until it reaches centre of lens then draw line across to meet with other lines
A concave (diverging) lens image will always be…
Virtual, upright, diminished
