properties of light and reflection Flashcards Preview

10 science-- optics > properties of light and reflection > Flashcards

Flashcards in properties of light and reflection Deck (35)
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1

medium

the substance through which light travels (air, water)

2

ray

a straight line with an arrowhead that shows the direction in which light waves are travelling

3

ray tracing

using rays to predict the location, size, and shape of the image of an opaque object

4

2 parts of fermat's principle

light follows the shortest straight line between two points
when light reflects into the same medium from which it originated, its speed will remain constant

5

reflection

change in direction of a light ray when it bounces off a surface

6

incident ray

a ray of light that travels from a light source toward a surface

7

angle of incidence

the angle between the incident ray and the normal

8

normal

a line that is perpendicular to a surface where a ray of light meets the surface

9

reflected ray

a ray that begins at a point where the incident ray and the normal meet

10

angle of reflection

the angle between the reflected ray and the normal

11

3 laws of reflection

incident ray, normal, and reflected ray lie on the same surface
angle reflection (r) = angle of incidence (i)
reflected ray and incident ray are on opposite sides of the normal

12

how to draw ray diagrams: step 1
draw the _____ using a ruler

incident

13

how to draw ray diagrams: step 2
at the contact point where the incident ray hits the surface, draw a ______ by measuring a __ degree angle with a protractor

normal / 90

14

how to draw ray diagrams: step 3
measure the longest ________ between the incident ray and the _____. make a mark to indicate the same angle on the other side of the normal. this is the ____________

angle of incident (i) / normal / angle of reflection

15

how to draw ray diagrams: step 4
draw the _________ from the contact point through the mark using a ruler

reflected ray

16

how to draw ray diagrams: step 5
what 5 things do you label?

incident ray
reflected ray
angle of incidence (i)
angle of reflection (r)
normal

17

why do we see objects in mirrors?

light rays are reflected off the objects and back to your eye

18

plane mirror

a mirror with a flat, reflective surface

19

step 1 of reflections:
when a light shines on the object, it reflects off all the points on the object in _________.

all directions

20

step 2 of reflections:
the rays reach the mirror, follow the ___________, and reflect toward your eye.

laws of reflection

21

step 2 of reflections:
even though the rays are reflected, your brain assumes light rays travel in a straight line, and treats them as if ____________

they had come form a point behind the mirror

22

how do we find out where the eye "sees" the image?

extend the reflected rays until they meet at a point behind the mirror

23

what kind of image forms? (L.O.S.T.)

location
orientation
size
type of image

24

location (L.O.S.T.)

image distance (distance between mirror and image) = object distance (distance between mirror and object)
image distance can be the same as, farther than, or closer than the object distance

25

orientation (L.O.S.T.)

upright, inverted, or reversed

26

size (L.O.S.T.)

image size = object size
size can be the same size, larger than, or smaller than the object

27

type of image (L.O.S.T.)

virtual image (forms behind mirror) or real (forms in front of mirror)

28

step one of ray diagram

incident ray from top of object horizontally to mirror surface, reflects back, extends behind mirror

29

step two of ray diagram

repeat 1, except from other points on object

30

step three of ray diagram

reflected ray from image to eye from all points