Grade 8 Optics – Objectives and Activities Kits/Optics 8... · Grade 8 Optics – Objectives and Activities ... (smooth) and diffuse (rough) ... OP8.3 Compare the nature and properties

Science 8 Resource Kit - Objectives & Activities 1|8

Grade 8 Optics – Objectives and Activities

Outcome: OP8.1 Identify and describe, through experimentation, sources and properties ofvisible light including: • rectilinear propagation • reflection • refraction.

Indicator (Question): Activities:1. Identify objects

(including those ofchemiluminescence orbioluminescence) asincandescence orfluorescence.

• Mentos & Tonic Fountain - handout OP8.1.1A (Steve Spangler Science(www.stevespangler.com)◦ Do regular “Coke and Mentos” experiment but in dark room with a

large black light.

• In Search of Phosphors activity – handout OP8.1.1B (Steve SpanglerScience)◦ Use a dark room and portable black light to determine things that

are phosphors

• Make your own glow sticks – handout OP8.1.1C(http://www.ehow.com/how_4844024_homemade-glow-sticks.html)

• Create Glow in the Dark Mountain Dew(http://www.youtube.com/watch?v=k2iM2LbCmQg)

• Research / Brainstorming activity: Generate a list of things that involvechemiluminescence (like a glow stick) or bioluminenescence (like anangler fish) and create a project showing information gleaned aboutthese items.

• Research activity: create an “at home experiment” to show how youcan create chemiluminescence.

2. Show how white light(natural light) can beseparated into aspectrum.

• Use a prism and shine different kinds of light (flashlight, flashlight withcoloured gels, laser) at it to see how it separates

• Make your own sun catchers/dreamcatchers – handout OP1.1.2A(http://www.ehow.com/how_7703523_make-crystal-suncatchers.html)

Sci 8 resource kit v. 2011


3. Investigate howshadows are formed andhow light travels instraight lines.

• Obtain a variety of objects (translucent, transparent and opaque) andput them in front of a window or source of light and see what happens.

• Create a pinhole camera – handout OP8.1.1.3A

4. Select appropriate toolsand use them toinvestigate properties oflight.

• “What is light” lab activity – handout OP8.1.1.4A

5. Discover specular(smooth) and diffuse(rough) reflection.a. Estimate angles of

incidence andreflection.

b. Explore the Law ofReflection and howit is used everyday(ex: sun dogs,rearview mirrors,magic tricks, etc.)

• Watch “Bill Nye – Optics” video to see an overview of refraction andreflection.

• Obtain a flashlight and a plane mirror. Shine the light on the mirror andobserve the spot that is reflected. Change the angle and discuss whatis happening with the students. If possible, see if students canmeasure angles with protractors.

• Students research their favourite magic trick involving mirrors. Theydemonstrate to the class and see if the other students can solve thetrick. Students could also record and youtube their magic stunts.

• View magic tricks by famous magicians (Houdini, Criss Angel) and seeif students can figure them out. Perform your own magic tricks too!(http://party-games-etc.com/magictricks.htm#livingshadows)

• Law of Reflection Activity – handout OP8.1.5A

• Students research sun dogs (and perhaps northern lights) and learnthe history behind them and write a 1-2 page story from a First Nationsperson's perspective (could also write a play or film their stories). Itwould be appropriate to share their stories with each other during thewinter months.

• Invite an elder to come to the class and share legends about sun dogsand light in First Nations cultures. (Tip: You will need to offer the eldera token, usually tobacco, and often story telling takes place only in thewinter.)

6. Explore why light bends(refraction) and differentdensities of materials(refractive index). a. Predict how light will

change whentraveling throughdifferent media

• Law of Refraction Activity – handout OP8.1.6A

• Imagination activity: Ask students why they can never catch minnowswhen they're at the lake.◦ Research (or view!) how bears and archer fish catch their food

using refraction.



(refraction.) • Try “Spear Fishing” with your students – put a pea in glass cup orbeaker. Fill it half full with water. Do the same thing to a secondbeaker but use oil (or any transparent material). Using a toothpickhave the students try to spear the pea. ◦ Ask which liquid was the easiest to use. ◦ Get the students to think about how First Nations groups who rely

on fishing could be so successful when they went spearfishing.◦ Ask students how they think other liquids would compare.

• Use the curved plastic dishes from the kit and a laser pointer orflashlight. ◦ Fill the dishes with different liquids (water, shampoo, oil, etc) and

shine the flashlight into the flat side of the dish. From above askthe students what they notice about the direction of the light. Havethem speculate about how light travels through other materials(diamond, ice, glass, plastic, etc).

◦ Option: place protractor under dish to view the changes in angle

OP8.2 Explore properties and applications of optics-related technologies, includingconcave and convex mirrors and lenses.

Indicator (Question): Activities:1. Identify materials that are

translucent, transparentand opaque.

• Concept formation:◦ Bring samples of various materials and objects from your home (or

the words or pictures of materials). Have groups of studentsgroup the materials together based on their similarities. - handoutOP8.2.1A

• Bring an example of each material to class and shine sources of lighton the materials. Have students explain how light behaves with thematerials.

2. Study how light interactswith convex andconcave mirrors andlenses and determinewhether the mirrors formreal (projected) or virtual(non-projected) images.a) Determine how

images are formedwhen objects aremoved to differentpositions in front ofthe mirror or lens.

• Perform “Curved Mirror” Lab activity – handout OP.2.2A – this can alsobe performed with the double convex lenses

• Shine lights on to various lenses and compare how the images look.

• Bring in a number of large metal spoons. Have the students viewthemselves in the concave (inward) part and observe themselves. Flipspoon so they view themselves in the convex (outward) side andcompare what they see.



3. Draw ray diagrams toshow how light travelsthrough different objectssuch as:a) pin hole camerasb) microscopesc) telescopesd) camerase) periscopes

• Create samples of the different objects(http://www.exploratorium.edu/science_explorer/periscope.html ,http://www.universetoday.com/17366/build-a-telescope/ ,http://www.rmcain.com/mcama/adv/adv4/advkids4.mv ) or obtain somematerials. ◦ Observe and study how the different elements reflect and refract

light. Google ray diagrams for these objects and compare notes.

4. Develop an experimentaldesign for a device usingoptics.a) Work with others to

develop a prototypefor the device

• See previous objective (OP8.2.3)

5. Identify optical devices thathave helped furtherinformation in differentfields.

• Students choose an area to research:◦ medicine (fibre optics, eye glasses)◦ telecommunication (ethernet cords, cable systems, etc)◦ brainstorm some of your own!

▪ Create a project to show they have learned about the deviceand how it has changed the field.

OP8.3 Compare the nature and properties of human vision with optical devices andvision in other living organisms.

Indicator (Question): Activities1. Investigate questions to

determine problems withhuman vision.

• Question students on eye vision problems that they know of. Sharewhat they know.◦ Research the vision problem – handout OP8.3.1A- to show what

they have learned. Create public service announcement ormedical brochure showing what the eye problem is, how it can becorrected, how much it costs, where it has to go to get fixed. ▪ Address how certain shaped lenses can aid with vision

problems.

2. Use a ray diagram to showhow light enters thehuman eye

• Use with “Cow Eye Dissection” activity (OP8.3.4)



3. Compare the human eyeto a camera.

• Have students study old film cameras and identify the camera partsthat are similar to:◦ pupil (aperture)◦ retina (screen; data collection material or film)◦ lens (lens)◦ ciliary muscles (zoom)

• Let students create a photo gallery showing how the parts of thecamera work like the eye (by changing aperture, for example, you canget blurry or brighter pictures – the same as if your pupil is dilated).

4. Compare human eyes toother vertebrate andinvertebrate animals.

• Cow eye dissection activity – handout OP8.3.4A, OP8.3.4B

• Discuss weird things that happen to your eyes:◦ red eye on pictures◦ why drugs/alcohol/stimulates/medications make your pupils dilate

• Try the Colour Blindness test: http://colorvisiontesting.com/online%20test.htm , http://colorvisiontesting.com/ishihara.htm )◦ Discuss the difficulties someone may have if they are colourblind.

5. Explain how colours areformed using theadditive and subtractivecolour process.

• Read The Magic School Bus Makes a Rainbow

• Obtain 3 flashlights from the kit and cover the ends with colouredcellophane (from the kit) in the primary colours ◦ Shine the coloured lights in a darkened room and see what

happens when you overlap the colours. (This works really well withspotlights and different gels. NOTE: it's hard to show the processof making yellow and also white light). You may also use colouredfilters or paddles on an overhead to show this effect.

• Show recumbent light: (how the colours add together to make whitelight: black and white to make colour:http://www.exploratorium.edu/snacks/benhams_disk/index.html;coloured disc to make white: http://www.kids-science-experiments.com/makeacolordiscspinningtop.html )

• Research how the phosphors on a TV work with the additive colourtheory.

6. Describe opticaltechnologies thatenhance human vision

• Can be included with objective OP8.3.1

• Discuss media trends (3-D TVs) that can harm vision and what thatmeans for emerging generations.



OP8.4 Evaluate the impact of electromagnetic radiation-based technologies on self andcommunity.

Indicator (Question) Activities1. Describe the

characteristics(frequency, wavelength,energy) of waves of theEM spectrum.a) Compare visible

light to other areasof the EM spectrum.

• Wavelength of a microwave activity – handout OP8.4.1A

2. Provide examples ofinstruments that emit EMradiation.

1. Cell phones2. Microwaves3. the Sun4. Fax machines5. Wireless

routers6. Tanning Beds7. etc.

b) Analyze thesedevices.

• Have each student choose an example of how EM waves are used.Have them teach the class about:◦ what the material is◦ what type of EM waves it gives off◦ what our lives would be like without it / how the waves affect us.◦ What some of the negative aspects of the device or waves are

3. Defend aposition/issue/problem(identified throughpersonal research) aboutthe impact of EMradiation.a) Identify new

problems that arisefrom the study ofEM waves.

• See above activity.

*NOTE: It would be interesting to include the study of plants and how they rely on light for their lifecycles. You couldeasily accomplish this by showing a video (Bill Nye and Magic School Bus are my favourite) on how plants grow. Youcould also address First Nation use of plants and other areas of herbology



Resources:

• Visualillusion.net (overall information that's good to use) -http://www.visualillusion.net/Chap14/

• Pearson Saskatchewan Science 8 – Has good background information and labactivities (many have been added as activity options)

• Steve Spangler Science - an interesting site with lots of simple demonstrations andactivities. - http://www.stevespanglerscience.com/



Kit Contents:Number Item In Kit?

1 • Laser pointer3 • Flashlight

3 each • Coloured cellophane◦ red◦ blue◦ green

◦ yellow◦ magenta◦ cyan

5 • Double concave lenses5 • Double convex lenses5 • Double concave mirrors5 • Double convex mirrors5 • Plane (flat) mirrors1 • “Bill Nye – Light Optics” DVD1 • The Magic School Bus Makes a

Rainbow soft cover book10 • Tea light candles5 • Plastic curved refractive dishes1 • Portable black light


Glowing Tonic Geyser

Add a little black light and tonic water glows a cool blue!

Tonic water might not be your first choice for a beverage, but it's the secret ingredient you'll

need to make a glowing geyser. It turns out that tonic water will glow under a black light because

tonic water contains quinine, a chemical that was originally added to tonic water to help fight off

malaria in places like India and Africa. While the tonic water we drink today only contains a

small amount of quinine, it's still enough to make your drink glow under black light. Combine

this with Steve Spangler's joy of shooting off soda geysers, and you have yourself a very cool

Halloween party idea.

Materials

Portable ultraviolet or black light

Bottle of tonic water (unopened)

Clear drinking glass

White sheet or posterboard

Darkened room

If you want to do Steve's Mentos Glowing Geyser demo, you'll need a roll of Mentos, a 2-liter

bottle of tonic water, and a Geyser Tube (or another creative way to drop the Mentos into the

soda).

http://www.stevespanglerscience.com/product/2072

http://www.stevespanglerscience.com/img/cache/bcb9b8db117ee64376aedaf7af3595ca/101707-tonicglow-1.jpg

Procedure:

1. Open the tonic water and pour some into a large, clear drinking glass.

2. Place a white sheet or poster board behind the glass to create a white background.

3. Turn off all the lights and completely darken the room. Turn on the black light and shine

it on the tonic water. Hey, what happened? The water is glowing blue!

Glowing Tonic Geyser

The following explanation uses the Geyser Tube as a triggering device for the glowing geyser.

1. You’ll need a 2-liter bottle of tonic water and an outdoor location for your geyser.

2. Start by tying one end of the string to the trigger pin (the string might already be attached

to the pin).

3. Open the bottle of tonic water and attach the Geyser Tube. Put the trigger pin into the

hole at the base of the Geyser Tube.

4. Twist off the top cap on the Geyser Tube and drop 7 MENTOS candies into the tube. The

trigger pin will keep the candy from falling into the soda… before you’re ready. Replace

the twist-on cap.

5. Warn everyone to stand back and turn on your black light. Countdown… 3-2-1… pull the

trigger. The MENTOS will drop and the tonic water will go flying into the air!

Remember that electricity and flying soda do not mix! It's best to use a battery powered black

light instead of anything that requires regular electricity from the wall.

How does it work?

The black light gives off UV light which is a higher energy light than visible light and the human

eye is not able to see it well. So, if ultraviolet light is virtually invisible, how can the tonic water

glow so brightly? The tonic water's color under the UV black light is fluorescent-blue because it

contains quinine, a substance that changes when it absorbs UV light. When the black light shines

on the tonic water, the tonic water absorbs the light and excites the electrons. Since the electrons

naturally want to return to their original relaxed state (who wouldn’t?), they give off energy that

has a wavelength in the blue part of the visible spectrum. That’s why the tonic water has an eerie

blue glow in the presence of ultraviolet light!

OP8.1.1C

How to Make Homemade Glow Sticks X

For a fun experiment for the science fair or just a do-it-yourself project at home, make homemade glow sticks. You can purchase the ingredients from online stores, but much of it is available at the supermarket if you know what to look for. For example, sodium carbonate is often sold in the laundry detergent aisle. Once you have the ingredients assembled and a clear workspace, you can begin.

Difficulty:

Moderately Challenging

Instructions

Things you'll need:

2 liters distilled water 50 milliliters hydrogen peroxide at a 3-percent concentration 0.5 grams ammonium carbonate 0.2 grams luminol 4 grams sodium carbonate 0.4 grams copper sulfate pentahydrate 2 glass bowls 3 or 4 test tubes with stoppers

Instructions:

1. Use a glass mixing bowl to mix 1 liter of water with the hydrogen peroxide. 2. Mix the sodium carbonate, luminol, copper sulfate and ammonium carbonate in another

glass bowl, along with 1 liter of water. 3. Hold out an open test tube and pour in 2 tablespoons of the first mixture. 4. Pour in 2 tablespoons of the second mixture and cap the test tube tightly. 5. Gently shake the test tube to mix the contents. As the chemical reaction begins, you'll see

the mixture start to glow--a result of the hydrogen peroxide solution oxidizing the luminol. The glow should last for a few minutes before fading.

Tips & Warnings

Be careful not to spill any of the substances on your skin or clothes, as several of them could cause a chemical reaction and irritate your skin or damage your clothing. Sensitive people also can have an allergic reaction

http://www.ehow.com/how_4844024_homemade-glow-sticks.html

OP1.1.2A

How to Make Crystal Suncatchers X

You can make suncatchers from glass or acrylic crystals. Suncatchers are sparkling window ornaments. They are made from transparent and glittering elements such as stained glass and colored plastic. You can make your own suncatchers from craft materials. Incorporating crystals into your homemade suncatchers can enhance their design, as the crystals will create brilliant patterns of sunlight on your walls. You can find crystals in craft stores and some furniture outlets. You can also use crystal drops intended for chandeliers, or glass pebbles and marbles. Large crystal beads can also be used very effectively.

Difficulty:

Moderately Easy

Instructions

Things you'll need:

Thick beading wire (12-gauge or larger) Fine beading wire (20- to 26-gauge) Small crystal beads Large crystal beads Crystals String Scissors Pliers Strong transparent glue such as cyanoacrylate adhesive or clear epoxy glue Screw hook or suction cup hook

http://i.ehow.com/images/a07/b2/v3/make-crystal-suncatchers-800X800.jpg

1. Form the basic outline of your design using the thicker-gauge wire. It's best if you start with a simple shape, such as a circle or a heart.

2. Secure any joins in the outline shape by wrapping a few turns of the fine beading wire around them. Bend the ends of the thick wire into decorative spirals and curls.

3. Wrap any crystals that are not predrilled with wire. Make a spiral with thick wire and place the crystal inside, or make baskets of fine beading wire to hold the crystals. You can add a small amount of glue to make the wire wrapping more stable. Make loops in the wire so you can hang your wrapped crystals.

4. Add wire loops to some of the larger crystal beads. Cut short sections of wire, and make a stop at one end of each by bending a little of the wire back with the pliers. (With softer wire you may be able to tie an overhand knot.) Slip a bead onto the wire, making sure it cannot slide over the stop. Make a loop in the other end of the wire.

5. Wind the fine beading wire around the outline of your suncatcher. String the small crystal beads on the fine wire as you go, letting the turns of wire hold them in place.\

6. Secure one or two crystals to the suncatcher. You can hang them from the top of your wire outline so they are framed by it, or you can hang them from the bottom of the wire outline like a pendant.

7. Cut a long section of thread. Fasten one end to the top of the suncatcher. 8. Set the screw hook into the frame at the top of your window. If your suncatcher is

small and light, you can use a suction cup hook that sticks to the window pane instead.

Just What is Light? Lab

Just what is light? This Lab activity is designed to get you thinking about what light is and how itbehaves. You will also be practising the different components of the scientific method.

Objective: to study some of the characteristics of light.

Directions:1. Start at the station designated to your group. You'll have 5 minutes at each station. Follow

the directions for each station and complete your work in this lab handout.

Station A: Mirrors• Make a hypothesis (your best guess) on what your image looks like when viewed with the

different sides of the mirror.____________________________________________________________________________________________________________________________________________________

• Observations:◦ What do you see when you look into the mirror?

______________________________________________________________________________________________________________________________________________▪ How does your image change from your real image?

____________________________________________________________________• Are you bigger or smaller? ___________________________________________• Are you upside down or right side up?__________________________________

◦ How does your image change when you look in the other side of the mirror?______________________________________________________________________________________________________________________________________________▪ How does your image change from your image in the other side?

____________________________________________________________________• Are you bigger or smaller than your regular image? _______________________• Are you upside down or right side up?__________________________________

Station B: Prism• Make a hypothesis about what you think will happen when you shine a light at a prism.

____________________________________________________________________________________________________________________________________________________

• Observations:◦ What happened when you shone the light at the prism?

______________________________________________________________________________________________________________________________________________

◦ What colour was the light to start with? _______________________________________▪ Was the colour the same after it hit the prism? _______________________________

◦ Did the light hit the prism and bounce off or go through?_______________________________________________________________________

Station C: Mixing light• Make a hypothesis about what you think will happen when you overlap three different

colours of light.____________________________________________________________________________________________________________________________________________________

• Observations:◦ What colour did you see when you overlapped:

▪ red and green? ________________▪ red and blue? _________________▪ blue and green? _________________▪ red, blue and green?_________________

Station D: Pencil• Make a hypothesis about what you think a pencil in a glass of water and in air will look like.

____________________________________________________________________________________________________________________________________________________

• Observations:◦ What did the pencil look like in the water?

______________________________________________________________________________________________________________________________________________

◦ What did the pencil look like in the air?______________________________________________________________________________________________________________________________________________

◦ Did looking at the pencil from different angles change anything? If so, what?______________________________________________________________________________________________________________________________________________

Station E: Lenses• Make a hypothesis about what you think will happen when you look at a piece of graph

paper through different parts of a lens.____________________________________________________________________________________________________________________________________________________

• Observations:◦ Using the lens that is thicker in the middle:

▪ What happened when you look at the paper through the middle of the lens?________________________________________________________________________________________________________________________________________

▪ What happened when you look at the paper through the edge of the lens?________________________________________________________________________________________________________________________________________

▪ What happened to the distances between the lines when you move the lens fartherfrom the paper?________________________________________________________________________________________________________________________________________

▪ What happened to the distances between the lines when you move the lens closer tothe paper?________________________________________________________________________________________________________________________________________

◦ Using the lens that is thinner in the middle:▪ What happened when you look at the paper through the middle of the lens?

________________________________________________________________________________________________________________________________________

▪ What happened when you look at the paper through the edge of the lens?________________________________________________________________________________________________________________________________________

▪ What happened to the distances between the lines when you move the lens fartherfrom the paper?________________________________________________________________________________________________________________________________________

▪ What happened to the distances between the lines when you move the lens closer tothe paper?________________________________________________________________________________________________________________________________________

Station F: Objects• Make a hypothesis about what you think will happen when you shine light at a glass, a

piece of waxed paper and a book.____________________________________________________________________________________________________________________________________________________

• Observations:▪ What happened when you shone the light at the glass?

________________________________________________________________________________________________________________________________________

▪ What happened when you shone the light at the waxed paper?________________________________________________________________________________________________________________________________________

▪ What happened when you shone the light on the book?________________________________________________________________________________________________________________________________________

▪ In your own words, write what you think each of the following means:• transparent

__________________________________________________________________________________________________________________________________

• translucent__________________________________________________________________________________________________________________________________

• opaque__________________________________________________________________________________________________________________________________

Analysis

Answer the following questions based on what you discovered in your lab activity.

1. Below is a list of words whose definitions you may or may not know. Working with apartner, sort the words you know into groups. Predict how each group represents ordemonstrates one of the key properties of light that you have explored so far. (7)

brightnessreflectionrefractiontranslucent

rainbowluminoustransparentwavelength

energycolourconcave mirror or lensconvex mirror or lens

a) Group 1:_______________________________________________________________________1. What is represented or demonstrated:

________________________________________________________________________________________________________________________________________

b) Group 2:_______________________________________________________________________1. What is represented or demonstrated:

________________________________________________________________________________________________________________________________________

c) Group 3:_______________________________________________________________________1. What is represented or demonstrated:

________________________________________________________________________________________________________________________________________

d) Group 4:_______________________________________________________________________1. What is represented or demonstrated:

________________________________________________________________________________________________________________________________________

e) Group 5:_______________________________________________________________________1. What is represented or demonstrated:

________________________________________________________________________________________________________________________________________

f) Group 6:_______________________________________________________________________1. What is represented or demonstrated:

________________________________________________________________________________________________________________________________________

g) Group 7:_______________________________________________________________________1. What is represented or demonstrated:

________________________________________________________________________________________________________________________________________

2. Have you thought about your future career? a) What is it? (1)

_______________________________________________________________________b) To do this career do you need to go to school after grade 12? (1) _________________c) How might optics (using the properties of light) and light be involved in your career? (2)

______________________________________________________________________________________________________________________________________________

3. Describe in one paragraph what you think are the properties of light energy. How do youknow? What could you find out about any properties of light that you're not sure about? (5)______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Just W

hat is Light? L

abStation A

: Mirrors

1.Write a hypothesis about w

hat you think your image w

ill look likein the concave and convex m

irrors.2.H

old up the mirror so the centre points out tow

ards you (concavem

irror). Look at yourself. What you you see? W

rite down your

observations.3.Flip the m

irror so that the centre is curved away from

you (convexm

irror). Look at yourself. What do you see? W

rite down your

observations.

Just W

hat is Light? L

abStation F

: Conducting light


ill happen when light is shone on: a

glass, a piece of waxed paper and a book.

2.Using the flashlight, shine the light onto each of the three objects.

Write your observations.

Just W

hat is Light? L

abStation B

: Using a S

pectroscop

e


ill happen to white light w

hen it islooked at through a spectroscope.

2.Point the spectroscope at the overhead lights with the slit pointing

towards the light (you look through the side w

ith the hole). What

do you see? Write dow

n your observations.

Just W

hat is Light? L

abStation D

: Bending P

encils


ill happen when you look at a pencil

standing in a glass of water.

2.Place a pencil in a glass half full with w

ater. Look at the pencilfrom

different angles. Write your observations.

Just W

hat is Light? L

abStation C: Coloured F

ilters


hat you think will happen w

hen thedifferent colours of light are added together.

2.Tape the yellow filter over one of the slits on the ray box. Tape the

red filter over the other ray box. Turn on the lights and aim the

colours on the screen so they over lap. Write your observations.

3.Turn off the lights and remove the red filter from

the ray box.Tape the blue filter over the slit on the ray box. Turn on the lightsand overlap the light again. W

rite your observations.4.Turn off the lights and rem

ove the yellow filter. Tape the red filter

over the slit on the ray box. Turn on the lights and overlap thecolours. W

rite your observations.5.Tape all 3 filters onto one ray box and shine the light on the screen.

Write your observations. Turn off the ray boxes and rem

ove thefilters.

Just W

hat is Light? L

abStation E: L

enses


ill happen to lined paper when you look

at it using a concave lens.2.H

old the lens in your hands and look at a piece of graph paperthrough the thick centre of the lens. W

rite your observations.3.N

ow look at the lines through the thinner edges of the lens. W

riteyour observations.

4.Move the lens closer to the paper and look through the w

hole lens. W

rite your observations.5.M

ove the lens further from the paper and look through the w

holelens. W

rite your observations.

Science 8 – Curved Mirrors Lab

Problem:• What are the characteristics and locations of images formed by an object located

at different places in front of a curved mirror?Materials:

• Metre stick• Candle• Converging mirror

Safety Precautions:• No baggy clothing; hair tied up and out of eyes.• Don’t reach across flame.• No papers in the flame.• Be careful with hot wax.• Use common sense.

Procedure:1. Hold the mirror in a dark part of the room and point it at the windows. Move a

blank piece of paper back and forth until the image of the windows is clearlyprojected on the paper. This is the focal length. Record this value.

2. Use the value you measured to determine the following distances:a. 2.5Fb. 2.0Fc. 1.5Fd. Fe. 0.5F

3. Place the mirror at the end of the meter stick. Move the lit candle to the firstlocation you calculated. Move the paper back and forth until an image is clearlyprojected. Record the image that you see, its attitude, size, type and distance. Fillin the chart started for you below. DO NOT START YOUR PAPER ON FIRE.

4. Repeat step 3 with the other 4 distances. Image distances aren’t needed forvirtual images.

5. Clean up the materials and return them to their original places. Wipe up any waxspills. Wash your hands.

Observations: (20)

Trial # ObjectDistance (do)

ImageDistance (di)

Characteristics

--- SizeAttitude (rightside up / upside

down)

Type (real /virtual)

abcde

Analysis:1. What is the focal length of the mirror? (/1)

______________________________________________________________2. As the object moves closer to the mirror, what general characteristics do you

notice about the image? (/1)______________________________________________________________

3. Where would you place an object in relation to the focal point to form a real image?______________________________________________________________A virtual image? (/2)______________________________________________________________

Conclusion:• What did you learn in this lab? (2)

__________________________________________________________________________________________________________________________________________________________________________________________

• What has this lab taught you about reflection of curved mirrors? (2)__________________________________________________________________________________________________________________________________________________________________________________________

• What do you think would be different if you used a convex mirror? (1)____________________________________________________________________________________________________________________________

Physics 20 – Application of Lenses 1

Application of Lenses There are many places where lenses are used other than for vision

correction.

You and a partner (of your choice – only two people per topic) are to

prepare, for your classmates a half page summary of an item that relies

on lenses to work.

Your page summation must include the following:

what it is, how lenses work in the item where it is commonly used

a picture (preferably a diagram illustrating how the lenses

work) Consequences if lenses could not be used (could it work

without a lens? How?)

How has this item shaped or changed our daily lives (think what you would do with out this item)

The source(s) of your information

You will be given 1 class to work on this; you may be given more class

time provided you prove that you deserve it.

Papers must be submitted by the beginning of class on Tuesday,

December 8th at the beginning of class. Watch the 5 day grace period!

Your peers will be the sole source of evaluation on this project. You will

be graded on the following criteria:

1. Is the information pertinent to the topic (i.e.: do they talk about lenses at all?)

2. Is the information concise and clear? Does it make sense?

3. Does it meet the required criteria? 4. Does it appear that the students have put in adequate effort?

5. Does the group appear to have analyzed the consequences of not

having the item?


Peer Evaluation – Application of Lenses: Project:

Criteria Yes (/4) No (/1) 1. Is the information

pertinent to the topic (i.e.: do they talk about lenses at all?)


3. Does it meet the required criteria?

4. Does it appear that the students have put in adequate effort?

5. Does the group appear to have analyzed the consequences of not having the item?

Assigned Grade /20

------------------------------------------------------------------------------------------------------- Peer Evaluation – Application of Lenses: Project:







Assigned Grade /20









Assigned Grade /20

------------------------------------------------------------------------------------------------------- Peer Evaluation – Application of Lenses: Project:







Assigned Grade /20









Assigned Grade /20

------------------------------------------------------------------------------------------------------- Peer Evaluation – Application of Lenses:

Project:





4. Does it appear that the students have put in

adequate effort?


Assigned Grade /20









Assigned Grade /20

---------------------------------------------------------------------------------------------------------------------- Peer Evaluation – Application of Lenses:

Project:






adequate effort?


Assigned Grade /20









Assigned Grade /20


Project:






adequate effort?


Assigned Grade /20









Assigned Grade /20


Project:






adequate effort?


Assigned Grade /20









Assigned Grade /20


Project:






adequate effort?


Assigned Grade /20

The Human Eye

Human eyes are crazy things! There's all kinds of physics going on in those babies.The most important thing to know is that without an understanding of refraction, wewould have no idea how the human eye works or how to correct problems associatedwith the eye.

Fill in the blanks on the above diagram. You will use the following words:CorneaLensIrisPupilRetinaOptic NerveVitreous HumourAqueous HumourScleraBlind Spot

With the materials you've been provided with, describe the function of each of the partsof the eye you just labelled.

Vision Problems & How they are Corrected

Normal vision:

• There are numerous kinds of vision problems that people encounter. We will focuson only a few of these and how corrective lenses (eye glasses) work to help theproblems.

• Farsightedness (hypermetropia) – This condition is when people have problemsclearly focusing on nearby objects, yet they can see objects at a distance fine.

• This is caused by a number of things, such as:◦ The lens isn't round enough◦ The distance between the lens and the retina is too short.

▪ What type of lens do you think would fix this?

• Nearsightedness (myopia) – This condition is when people have problems clearlyfocusing on distance objects. Objects near the person can be seen clearly.

• This may be caused because the lens isn't powerful enough to focus the light onthe retina, or the distance between the lens and the retina is quite far.

▪ What type of lens do you think fixes this?

• What is colourblindness?◦ People who are colourblind have the inability to distinguish clearly between

different hues of colour. There are many reasons why people are colourblind.Some reasons are because of genetics, or injury to the head or eye.

◦ Different types of colourblindness:▪ Monochromacity – all colours look the same; also known as total

colourblindness▪ Dichromacity – this is the most common type of colourblindess and is

usually called red-green colourblindess. It is a sex-linked trait thataffects only males. With this colourblindness, people cannot clearlydistinguish between colours containing shades of red or shades of green.• There is also a rare case called tritanopia. This is where the person

does not have blue colour receptors.◦ The cells responsible for us seeing in colour are called rods and cones.

• Did you know:◦ You can't clearly focus your eyes on two objects at once.◦ Your eyes can adjust between focusing on distant objects and nearby objects

very quickly. This is called: ◦ Benjamin Franklin invented bifocals.

▪ Bifocals are two different lenses: one for seeing close things clearly andone for seeing distant things clearly.• As you get older, the muscles in your body begin to lose their elasticity.

This happens with your eyes too. That means that many older peoplehave difficulties switching between seeing things clearly at differentdistances. This is why they get bifocals.

Documents

Grade 8 Optics – Objectives and Activities Kits/Optics 8... · Grade 8 Optics – Objectives and Activities ... (smooth) and diffuse (rough) ... OP8.3 Compare the nature and properties