PHYSICS

Question 1

Wave

Answer 1

disturbance that transfers energy from one point to another w/o transferring matter

Question 2

Medium

Answer 2

type of matter the wave is travelling therough

Question 3

Amplitude

Answer 3

wave height/depth from the rest position

Question 4

Frequency

Answer 4

the rate of repetition of a wave

Question 5

relationship between frequency and wavelength

Answer 5

higher frequency = higher energy = higher amplitude = shorter wavelength

Question 6

electromagnetic radiation

Answer 6

wave pattern made of electric and magnetic fields, travel through empty space

Question 7

additive colour theory

Answer 7

lights have colours, that when combined, they create new colours

Question 8

subtractive colour theory

Answer 8

coloured matter selectively absorbs diff colours (wavelengths) of light

• absorbed colours cannot be seen
• not-absorbed colours are seen

Question 9

Bioluminescence

Answer 9

ability of a plant or animal to produce light (ie. jellyfish)

Question 10

Incandescent

Answer 10

by an object that is at very high temperatures (ie. filament in lightbulbs)

Question 11

Fluorescent

Answer 11

emitted by a substance when exposed to electromagnetic radiation (fluorescent light bulb)

Question 12

Triboluminescence

Answer 12

by friction (rubbing two quartz)

Question 13

Phosphorescent

Answer 13

stored light (energy) slowly emitted over time (glow in the dark toys)

Question 14

Chemiluminescence

Answer 14

light from a chemical reaction (glow sticks)

Question 15

Electroluminescence

Answer 15

transforming electrical energy directly into light energy (LED)

Question 16

Electric Discharge

Answer 16

electric current passes through the air or gas (lightning, neon lighting sign)

Question 17

transparent

Answer 17

transmits light freely (reflects very little)

Question 18

translucent

Answer 18

transmits some light, not enough to see through clearly

Question 19

opaque

Answer 19

absorbs or reflects all light but does not transmit light

Question 19

Regular reflection

Answer 19

all rays reflected at same angles so they reach your eyes (allows us to see image in reflection)

Question 20

shadows

Answer 20

• opaque object blocks direct light
  umbra: part of shadow in which all light rays from source are blocked
  penumbra: area of partial shadow

Question 21

Diffuse reflection

Answer 21

rays reflect off a rough or uneven surface –> do not remain parallel to one another –> Does not allow for image reflection

Question 22

law of reflection

Answer 22

the angle of incidence is always equal to the angle of reflection

Question 23

Concave mirror

Answer 23

curves away, converging, real or virtual images that are magnified or reduced or inverted

Question 24

Convex mirror

Answer 24

curves towards you, diverging, produces images that is virtual, upright, reduced

Question 25

Refraction

Answer 25

bending of light as it passes from one medium into another (when light moves from one medium to another, the direction and speed change ) - speed of light decreases as angle of refraction becomes smaller

Question 26

RULES FOR REFRACTION

Answer 26

1. if speed of light in SECOND medium is LESS than speed of light in FIRST medium, will BEND TOWARD from normal 2. if speed of light in SECOND medium is GREATER than speed of light in FIRST medium, will BEND AWAY from normal

Question 27

Dispersion

Answer 27

process of separating colors by refraction

Question 28

total internal reflection

Answer 28

light reflects completely off the inner boundary of a denser medium rather than passing through

Question 29

Mirage

Answer 29

image of distant object produced as light refracts through air of different densities - as light rays passes through layers of air w/ progressively lower indexes of refraction, eventually the light is totally internally reflected to create the reflection (the mirage)

Question 30

Fibre Optics

Answer 30

thin transparent glass tube that can transmit light, even around corners, (light cant escape so travels all the way to the end)

Question 31

optic centre

Answer 31

where optical axis and principal axis meet

Question 32

principal focus

Answer 32

where the light rays parallel to PA converge after refraction

Question 33

axis of symmetry

Answer 33

an imaginary vertical line is drawn through optical centre of lens

Question 34

Concave/converging lense

Answer 34

converge through a single point after refraction through lens

Question 35

Convex/ diverging

Answer 35

rays diverge and will not meet on the other side of the lens

Question 36

Perception

Answer 36

ability to interpret info about the surroundings from the effects of visible light reaching the eye

Question 37

Optometrist

Answer 37

a professional trained to test vision

Question 38

Ophthalmologist

Answer 38

a specialized eye surgeon

Question 40

Cornea

Answer 40

light rays are refracted by the cornea to direct light correctly to your eye

Question 41

Pupil

Answer 41

a hole that allows light to pass into the eye

Question 42

Iris

Answer 42

controls size of pupil --> controls amount of light that enters eye

Question 43

Retina

Answer 43

inner lining at the back of the eye that acts as a screen for light rays entering your eyes

Question 44

Ciliary muscles

Answer 44

adjust your focus (can make it round to see distant objects or flatten to see close objects)

Question 45

detecting light

Answer 45

light is absorbed by photoreceptors (cells in the retina that are sensitive to light)

Question 46

Rod cells

Answer 46

help to detect shape and movements in low light (only see gray)

Question 47

cone cells

Answer 47

used to detect color. Three types, each of which detects a different primary colour well

Question 48

near-sitted

Answer 48

see nearby objects but cannot see distant objects

Question 49

far-sitted

Answer 49

see distant objects clearly but cannot see nearby objects