Normal Line Incident RayReflected Ray <i<r <i = <r

 1. <i is equal to <r  2. Incident ray, reflected ray and the normal all lie in the same plane.

Mirror

S izeSmaller vs. Same vs. Larger A ttitudeUprightvs. Inverted L ocationWhere the image is located T ypeReal vs. Virtual

 Incident rays entering to a “Cave”  Concave = converging C V F Principal axis

 Image on SAME SIDE as object = REAL  Image behind the mirror = VIRTUAL Object REAL Image VIRTUAL Image

 Simply use 2 of the rules C V F

If object is at F = no clear image F VC Lines do not meet up

If object is between F and V = Virtual image F VC

 Incident rays”bouncing off a ball”  Convex = diverging VF Principal axis C

 Incident rays ”bouncing off a ball”  Image is ALWAYS smaller and virtual VFC

Bending of light when it travels from one medium to another If SLOWING down when entering another medium  bend TOWARDS the normal Normal Line Incident Ray <i Medium A (Faster\) Medium B (Slower) <R Refracted Ray

If SPEEDING UP when entering the medium  bend AWAY from the normal Normal Line Incident Ray <i Medium A (Slower) Medium B (Faster) <R Refracted Ray

 Either use:  n = c. OR n = sin <i.  v sin <R  Example 1:  Speed of light in air is 3.00 x 10 8 m/s. Speed of light in salt is 1.96 x 10 8 m/s. Light enters from air to salt. Which way does the light bend? What is the index of refraction?

 Either use:  n = c. OR n = sin <i  v sin <R  Example 2:  Index of refraction of quartz is If the angle of incident ray from air is 60 0, what is the angle of refracted ray in quartz?

ONLY occurs under 2 conditions: 1. Light is travelling more slowly in 1 st medium than in 2 nd medium (going from SLOWER to FASTER) 2. Angle of incidence is GREATER than critical angle

Normal Line Air (FASTER) Water (SLOWER) Critical angle

 F = principal focus  F’ = secondary principal focus  O = optical centre F’2FF Principal axis 2F’ O

 If Image is on the OPPOSITE SIDE of the lens from the object = REAL Image  If Image is on the SAME SIDE as object = Virtual Image REAL Image ObjectVIRTUAL Image

 Simply use 2 of the rules F’2FF2F’ O

 The only time you’ll get VIRTUAL image with converging lens is when the object is between F’ and O F’2FF2F’ O

F = principal focus F’ = secondary principal focus O = optical centre F2F’F’ Principal axis 2F O

Always the SAME image characteristics no matter where the object is located: Smaller, upright, virtual, same side as object. F2F’F’ Principal axis 2F O

1 + 1 = 1 d o d i f Object F’2F F 2F’ O Image do ff di ho hi

1 + 1 = 1 d o d i f d o is always + d i is + for real image - for virtual image f is + for converging lens - for diverging lens M = h i = - d i h o d o h 0 and h 1 are: + when measured upward - when measured downward M is: + for upright image - for inverted image