1. Light Part 2

2. Reflection Occurs when waves traveling in one media reach a boundary with another media and bounce back into the first medium Total Reflection  all of the wave energy is transmitted back Partial Reflection  some of the wave energy is transmitted into the new medium

3. Reflection Amount of reflection is dependent on the rigidity of the media Metals  very rigid; reflect most light Glass/Water  not as rigid to light waves; allows waves to pass through

4. Law of Reflection Incident waves and reflected waves make equal angles with a line perpendicular to the surface, called the normal. Angle of Incidence  angle made by the incidence wave and the normal Angle of Reflection  angle made by the reflected wave and the normal

5. Mirrors Virtual Images  images seen in a mirror that appear to originate behind the mirror Light does not pass through the image position, but behaves like it does Convex Mirror  creates virtual images smaller and closer to the mirror Concave Mirror  creates virtual images larger and farther away

6. Mirrors Mirror Equation 1/p + 1/q = 1/f p  object distance (d o ) q  image distance (d i ) f  focal length Object and image distance are positive when measured from center of mirror to any point in front of mirror Object and image distance are positive when measured from center of mirror to any point in front of mirror Object and image heights are positive when above the principle axis and negative below Object and image heights are positive when above the principle axis and negative below

7. Mirrors Focal Length of a curved mirror is one half the radius of curvature Concave Mirror  focal length is positive Convex Mirror  focal length is negative

8. Mirrors Magnification Equation M = h i /h o = -q/p M is positive when the image is in front of the mirror and inverted M is negative when the image is behind the mirror and upright

9. Reflection of Sound Echoes  sound reflects better off large, rigid, smooth surfaces  reflects less if the surface is irregular and soft Acoustics  study of the reflective properties of sound Reverberations  garbled sound caused by multiple reflections

10. Refraction The bending of waves that results from waves being made to travel more slowly (or quickly) than another part

11. Refraction of Sound Refracted due to differences of media or difference within a media Warm Air  waves bend away from the ground and seem to not carry well Cold Air  waves bend toward the ground and seem to carry well

12. Refraction of Light When one part of the ray is made to travel more slowly than another, the rays are refracted closer to the normal Causes pools and ponds to appear shallower than they are since the speed of light is changed when the light waves move from air into water

13. Refraction of Light Atmospheric  Mirages  very hot air close to the ground causes a speeding up and bending of light waves, producing an image  image would appear upside down to the observer just as if it were reflected off of water, but it is refracted

14. Snell’s Law n 1 sin  1 = n 2 sin  2 n  index of refraction  1  angle of incidence  2  angle of refraction