science - reflecting and absorbing light

Question 1

what is a luminous object?

Answer 1

an object which can produce light by itself

Question 2

what is a non-luminous object?

Answer 2

an object which cannot produce light by itselft therefor it reflects light.

Question 3

what does reflect mean

Answer 3

to bounce off a surface

Question 4

what does absorbing mean

Answer 4

when a material does not let light energy to pass through so instead it is absorbed by the material

Question 5

how many colours is white light made up of

Answer 5

7

Question 6

what are those colours

Answer 6

red, orange, yellow, green, blue, indigo and violet.

Question 7

each colour has different frequencys. Which colour has the lowest frequency

Answer 7

red

Question 8

Which colour has the greatest frequency

Answer 8

violet

Question 9

true or false? Different filters will allow different colours to pass through.

Answer 9

true

Question 10

true or false? if the colours do not pass through they will be absorbed

Answer 10

true

Question 11

what does transparent mean

Answer 11

all light passes through

Question 12

what does translucent mean

Answer 12

some light is blocked off

Question 13

true or false? light travels in a straight line

Answer 13

true

Question 14

what does opaque mean

Answer 14

no light passes through

Question 15

true or false? the speed of light is 300,000 cm/s

Answer 15

false, The speed of light is 300,000 km/s

Question 15

What does specular reflection mean

Answer 15

if the surface is smooth and flat then it will reflect in parallel rays and will produce a clear image

Question 16

what does diffuse reflection mean

Answer 16

when it reflects off a rough, bumpy surface and produces a blurry image

Question 17

what does the normal mean

Answer 17

an imaginary line at 90 degrees to the mirror

Question 18

what does the incident ray mean

Answer 18

the ray of light that hits the surface of the mirror

Question 19

what does the reflected ray mean

Answer 19

the ray that reflects off the mirror

Question 20

what does the angle of incidence mean

Answer 20

angle between the incident ray and the normal

Question 21

what does the angle of reflection mean

Answer 21

angle between the normal and the reflected ray

Question 22

what is the material that a wave travels through called

Answer 22

a medium

Question 23

what happens when light is absorbed

Answer 23

energy is transferred through the material

Question 24

what is refraction?

Answer 24

when light passes through 2 different materials, it can change speed,

Question 25

what is the law of reflection

Answer 25

angle of incidence is EQUAL to the angle of reflection

Question 26

what does a convex lens look like

Answer 26

a piece of transparent material like glass or plastic that is thin around the edges but has a thick center. Looks like an oval/circle

Question 27

what does a convex lens do?

Answer 27

it helps people if they are shortsighted by focusing light inwards

Question 28

what is a concave lens/what does it look like

Answer 28

a piece of transparent material like glass or plastic that is thick around the edges but has a thing center. Looks like a rectangle however the long sides curve inwards to make sure that light is spread out

Question 29

if an image is close, is the lens thick or thin

Answer 29

thick

Question 30

if an image is far away, is the lens thick or thin?

Answer 30

thin

Question 31

what does the cornea do?

Answer 31

controls and focus the entry of light into the eye

Question 32

what does the iris do

Answer 32

regulates the amount of light that enters the eye

Question 33

what does the pupil do

Answer 33

allows light to enter the eye so it can be focused on the retina

Question 34

what does the lens do

Answer 34

absorbs, focuses and directs the light to the retina

Question 35

what does the cillary muscle do

Answer 35

changes the shape of the lens

Question 36

what does the retina do

Answer 36

senses light and sends signals to the brain

Question 37

what does the optic nerve do

Answer 37

lets retina to send information to the brain

Question 38

true or false? the shorter the focal length, the more powerful the lens is?

Answer 38

true

Question 39

what is the focal length

Answer 39

distance between the center of a lens and its focus

Question 40

what is the principle focus

Answer 40

the point on the principle axis of the lens at which an object is placed