physics unit 1

Question 1

what is light?

Answer 1

• energy
• travels in particles
• wave-like properties (particle duality)
• travels at 300 000 000 m/s in a vacuum

Question 2

what is quantum mechanics?

Answer 2

light moves in both waves and as a particle

Question 3

how does light carry energy from one medium to another?

Answer 3

electromagnetic waves

Question 4

list the electromagnetic spectrum from least to greatest energy

Answer 4

radio waves, microwaves, infrared light (bodies emit), visible light, UV, X rays, gramma rays

Question 5

what effects wave length?

Answer 5

Quanta (amount of energy), wave length and energy amount can very but not the speed at which it travels

Question 6

what are luminous and non-luminous visible light sources??

Answer 6

luminous: produces its own light (the sun)
non-luminous: reflects light (counter top)

Question 7

what are the luminous sources??

Answer 7

Incandescence: high temp heating a filament
electric discharge: passing through electric current (lightning)
Fluorescence: immediate emission of visible light from absorption of UV
phosphorescence: absorption of UV resulting in extension of light emitted (glow in the dark toy)
chemiluminescence: direct production of chemical reaction with no heat (light sticks)
Bioluminescence: light in living organisms (firefly)
Triboluminescence: from friction of scratching, rubbing, or crushing (ex. rubbing two quartz together)
light emitting diode: electric current-flowing in semiconductors (LED light bulb)

Question 8

what direction does light radiate in??

Answer 8

straight in all directions

Question 9

what is geometric optics??

Answer 9

using light rays to determine how light behaves when it strikes an object

Question 10

Explain transparent, translucent, and opaque??

Answer 10

transparent: clear
translucent: foggy
Opaque: soild

Question 11

plane mirror terminology:
plane:
indient ray:
reflected ray:
normal:
angle of incidence:
angle of reflection:

Answer 11

plane: flat
incident ray: incoming ray striking a surface
reflected ray: ray bouncing off reflective surface
normal: perpendicular line mirror to surface
angle of incidence: angle between incident/normal
angle of reflection: angle between reflective/normal

Question 12

what does S.A.L.T stand for??

Answer 12

s: size (image larger/smaller/or smae size as object)
a: attitude (image upright/inverted)
l: location (where)
t: type (real/ virtual)

Question 13

what is a concave mirror?

Answer 13

converging, inner surface is reflective (satellite dish, makeup mirrors)

Question 14

what is a convex mirror?

Answer 14

diverging, outer surface is reflective (magnifying glass, telescope)

Question 15

what does the C, F, and V on a curved mirror represent?

Answer 15

C: centre of curvature
F:the point at which light rays are parallel to the principal axis coverage, always between C and V
P: principal axis
V:vertex

Question 16

general rules for a concave mirror?

Answer 16

1. light ray parallel to the principal axis is reflected through F
2. light ray through c reflects back onto itself
3. light ray through F is reflected parallel to P
4. light ray through V follows law of reflection

Question 17

what is refraction and its 3 rules?

Answer 17

refraction: the bending of light when it travels between mediums

rule 1: incident ray, normal, and refracted ray are all on the same plane
rule 2: light beds towards the normal when it stays down and away from the normal when it speeds up

Question 18

rules for a convex mirror?

Answer 18

1. light ray parallel to P is reflected through as if it had come from F
2. light ray aimed at C is reflected back onto itself
3. light ray aimed at F is reflected back onto itself
4. light ray through V follows law of reflection (angle of incidence=angle of reflection)

Question 19

what does it mean when light mnemonic?

Answer 19

it speeds away

Question 20

what is the critical angle?

Answer 20

angle of incidence resulting in a refraction angle of 90 degrees

Question 21

what is total internal reflection?

Answer 21

the situation when an angle of incidence is greater than the critical angle

Question 22

do, di, and f

Answer 22

d0-distance from object to optical centre
di- distance from image to optical centre
f- focal length of lens; distance from optical centre to principal F

Question 23

if di is on the same side as object:

if f is on the same side as object:

Answer 23

• its negative
• f is negative

Question 24

what are the 3 ways light interacts with matter

Answer 24

-emit light
- absorb light
- transmit light
- reflect (or scatter) light