physical science test 3

law of reflection

<i=<r angle of incident = angle of reflection

convex mirror types

ALWAYS VITUAL example bus, security mirror( store classroom,) hopital, passenger mirror

Be able to draw a sketch showing why convex mirrors let you see more than a flat mirror. Diagram on reflection lab 3 number 10

EDEN

Know how parallel light rays reflect off of concave and convex mirrors ( diagram # 1 and 8)

Eden

be able to show how light reflects off flat convex and concave mirrors ( reflection lab 1 # 11 and 6)

Eden

draw ALLLLLLL diagrams from color lab 3 and explain answers colored paper and car ones ALLLLL

Eden

go over last page of reflection lab 2

Eden

know how to draw reflection imiages using the methods- reflection lab 2 # 18,23,14 and 10)

Eden

review assignments

Eden

what do convex mirrors produce?

ONLY VIRTUAL images

If you stare at one color for a long time and then look at a white object why does the color change?

When you stare at 1 color for a long time your cones which are responsible for seeing color get tired and and the white paper reflects red, blue and green light but if one or more of the cones are tired then you wont see that/those colors, but you will see the rest

Does the law of reflection hold true for both specular (smooth surfaces) and diffuse (rough surfaces) reflection? Why?

YES! <i=<r paper is rough and has all kinds of normal lines and the bumps cause light to scatter and both specular and diffuse reflection incident rays and reflected rays equal each other so therefore the law of reflection is works for both specular and diffuse

What is the difference between additive and subtractive color mixing?

additive color mixing is when you add colors together which makes new colors by adding the colors together ( light, blue+red= magenta) subtractive color mixing is when you mix different colors of pigment and you take away colors of light to produce new colors ( if you have a yellow and red filter you see red)

normal line definition

any line that is perpendicular to a surface

Where are images located in plane (flat) mirrors?

behind the mirror

What colors do you get when you mix the different primary colors of light?

blue and red= magenta blue and green= cyan red and green= yellow

If you stare at .blue, green or red what color will you see?

blue- yellow green- magenta red-cyan

be able to draw and describe specular and diffuse reflection ( diagrams on color and reflection assignment #14)

diffuse reflection scatters light and specular reflection does not

Know how a concave mirror can be used to make a beam of light. Know examples of items that do this and be able to draw/explain how it happens diagram on reflection lab 3 #3

examples: flashlight, spotlight, headlight, lasers the light comes from a focal point reflects off the mirror in parallel rays

incident ray definition

incoming ray of light

how do you make grey

little green, little blue , little red

What are the primary colors of pigments, what colors do you get when you mix them?

magenta, cyan and yellow magenta+cyan=blue cyan+yellow=green magenta+yellow=red

how do you make light blue

more blue less green

how do you make purple

more blue less red

how do you make pink

more red less blue

concave mirrors 3 type

no image- use a concave mirror to make a beam of light( spotlight, flashlight head light) virtual image- make up mirror real image- telescope

Know how glass reflects light and some applications/examples for that know diagrams on note page

normal glass reflects 5% of the light that hits the mirror and 95% goes through glass can be coated to reflect more than 5% of light ( sunglasses, tinted windows)

how do you get orange in light

orange= a lot of red and a little green( more red than green)

primary colors light secondary colors light complementary colors light

p- blue green red S- magenta, yellow, cyan C- yellow and blue, magenta and green, cyan and red

What are some devices that use primary colors of pigments?

paint, crayons, printer, markers, highlighter

In general, know the four methods for finding the location of those images. Be able to apply the methods when necessary.

parallax- you guess where your focusing and move your head side to side ray drawing- extend reflected rays to find the image measuring- measure the distance from each point to the mirror then draw the same distance on the other side trace and fold- trace the image with pen/pencil, fold the paper on the mirror line and rub where the object is and the image will will go in the correct location

How do you get colors like purple, or black in light?

purple= 1/2 of red and 1/2 of blue black= 0 parts of each color/ no colors

reflected ray definition

ray of light after it reflects off the mirror

Be able to give an example of things that use concave mirrors to make either a real or a virtual image, and be able to explain them.

real- telescope virtual-make up mirror telescope takes a picture and makes the image looks brighter make up mirrors makes an image closer up

what are the 2 types of reflections?

specular and diffuse

what is the difference between diffuse and specular reflection

specular is when light hits a mirror and almost all of it reflects in the same direction so you can see a reflection(example is glass, water) diffuse is when the light hits a rough surface and almost all the light explodes off the rough surface

know some places where you might find convex mirrors.

stores ( to find shoplifters) passenger side mirror classroom hospital( to see if anyones coming when you go around a corner)

draw diagrams of what color you see with different filters on color and light lab 2 do # 4-18 until you get it and can explain them is this additive or subtractive mixing?

subtractive because you keep subtracting colors to get a new color

be able to use a protractor and measure angle of incidence and reflection from the normal line and LABLE 5 Parts and draw normal line (reflection lab 1 question 6)

the 5 parts: normal line, incident ray, incident angle, reflected ray, reflected angle

angle of reflection definition

the angle between the normal and the reflected ray

angle of incidence definition

the angle between the normal line and the incident ray

When you cover the green and blue filter, you should get black. Why did that not happen?

the blue and green wavelengths are about the same and its difficult for the filter to only let through blue or only let through green.therefore the blue filter lets through a little green and the green filter lets through a little blue creating a dark cyan

primary color definition

the colors that can be mixed to form all other colors, you cannot mix other colors to make primary colors

What do color filters do when light hits them?

the filters absorb certain colors of light and let through other colors

Be able to describe the path light takes when looking at objects in a mirror. when your looking at something else: when your looking at your reflection:

the light has to hit the object(diffuse), reflect to the mirror(specular) then go to your eye your reflection: the light has to hit you(diffuse), reflect to the mirror (specular), then go to your eye

Know how the image in a flat mirror looks different than the actual object.

the object and the image are the same distance from the mirror. the line that connects the object and image is perpendicular to the mirror, and the words will look backwards

where are your rods located?

there located around the edges of your eye

where are your cones located?

there located near the center of your eye

Know how the Levitating, thing works

there's a mirror placed diagonally in a "box" and 1 foot is placed in front of the mirror and the other is behind the mirror. the object( foot) and the image( other foot) are the same distance from the mirror and the line that connects the image and object together is perpendicular to the mirror. to make it look like your floating you need to lift only the foot that is in front of the mirror because to the audience it looks like both feet are "floating". WHen really they see the foot in front of the mirror lifting and the reflection of that foot because the image was located the back foot was placed

complementary colors (of light) definition

these are to 2 colors that when they mix they produce white light

secondary color definition

these colors are formed by mixing 2 primary colors in equal amounts

what do your cones do?

they allow you to see color during the day

what is the main USE of convex mirrors

to see more

what devices use primary colors of light

tv's, computer, phone

Know the differences between real and virtual images.

virtual image is when light rays spread out after they hit the mirror and the light rays appear to cross behind the mirror, these image are always right side up and cant be focused on papers/screen real image is when the light ray actually does cross after hitting the mirror. these images are always up side down and can be focused on paper/screen. ( object must be placed behind focal point

how does your eye see color? example: and orange ( whats coming down what colors are reflecting off and what is happening in your eye) DIAGRAM!!!! color lab 4, back page

white light ( red, green blue) shines on the orange. Red and a little green reflect (blue is absorbed) your eye makes an upside down picture on the retina. The red cones turns turn on brighter than the green and they send a message to the brain( because orange is more red less green) and the brain automatically flips the image

how do you get white in light

white= when you mix all the primary colors together or you mix the complementary colors together ( green and magenta, yellow and blue, cyan and red)

what are your rods for

you rods allow you to see light when it is dark outside