Ch 8 - Light and Optics Flashcards Preview

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Flashcards in Ch 8 - Light and Optics Deck (73)
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1

electromagnetic spectrum from lowest energy to highest energy

radio waves (wavelength range from 10^9 - 1 m), microwaves (1 m - 1 mm), infrared (1 mm - 700 nm), visible light (700 nm - 400 nm), ultraviolet (400 - 50 nm), x-rays (50 - 10^-2 nm), gamma rays (less than 10^-2 nm)

2

electromagnetic waves

transverse waves - oscillating electric and magnetic field vectors are perpendicular to the direction of propagation and each field is perpendicular to each other.

3

common units of wavelength

mm (10^-3 m), fancy um (mu) (10^-6 m), nm (10^9 m) and A with a circle at the point (angstrom, 10^-10 m)

4

visible spectrum from lowest to highest energy

Red, orange, yellow, green, blue, violet (roy g bv)

5

speed of light

EM waves travel this fast in a vacuum and in air: c = 3.00 x 10^8 m/s

6

equation for speed of light

c = f x wavelength; f = frequency; c = speed of light in air and vacuum

7

approximate wavelength boundaries of the visible spectrum

400-700 nm

8

blackbody

ideal absorber of all wavelengths of light, which would appear completely back if it were at a lower temp than its surroundings

9

rectilinear propagation

concept that light travelling through a homogenous medium will travel in a straight line

10

reflection

rebounding of incident light waves at the boundary of a medium

11

law of reflection

theta sub 1 = theta sub 2 (angles of reflection); theta sub 1 = angle of incident and theta sub 2 = reflected angle

12

normal (in reference to reflection)

a line drawn perpendicular to the boundary of a medium; all angles in optics are measured from the normal, not the surface of the medium

13

real image

image in which the light actually converges at the position of the image; this image can be projected onto a screen

14

virtual image

image in which the light only appears to be coming from the position of the image but does not actually converge there

15

plane mirrors

flat reflective surfaces that cause neither convergence nor divergence of reflected light rays; because light does not converge at all, these always created virtual images because reflected light remains in front of the mirror but the image appears behind the mirror

16

spherical mirrors

come in two varieties: concave and convex and have associated center of curvature (C) and radius of curvature (r)

17

center of curvature

point on the optical axis located at a distance equal to the radius of curvature from the vertex of the mirror; the center of the spherically shaped mirror if it were a complete sphere

18

concave mirror

also called converging mirrors; edges coming towards you; center of curvature and radius of curvature are located in front of the mirror

19

convex

also called diverging mirrors; surface coming towards you; edges away; center of curvature and radius of curvature are behind the mirror

20

focal length (f) of mirror

distance between focal point (F) and mirror

21

focal length for spherical mirror

f = r/2 where radius of curvature (r) is distance between C (center of curvature) and the mirror

22

relationship between four important distances of spherical mirrors

1/f = 1/o + 1/i = 2/r; where f = focal length, o = distance between object and mirror, i = distance between image and mirror, r = radius of curvature

23

image distance greater than 0

real image which implies that the image is in front of the mirror

24

image distance less than 0

virtual image; image is behind the mirror

25

magnification (m)

dimensionless value that is the ratio of the image distance to the object distance (m = -i/o); also gives ratio of the size of the image to the size of the object

26

inverted image

negative magnification value

27

upright image

positive magnification value

28

what happens to image where |m| < 1

image is smaller than object

29

what happens to image if |m| > 1

image is larger than the object

30

what happens if image is |m| = 1

image is same size as object