bc science 8 ch04 - · pdf fileuse with textbook pages 134–138. true or false? read the...

50 MHR • Section 4.1 Properties of Waves © 2006 McGraw-Hill Ryerson Limited

Properties of WavesTextbook pages 134–143

Before You ReadIn this section, you will find out about waves, such as water waves, sound waves, andradio waves. On the lines below, list devices you use that make or use waves.

_______________________________________________________________________________________

_______________________________________________________________________________________

Name Date

What are the features of a wave?

A wave is a movement that transfers energy through matter orspace. Energy is the ability to apply a push or pull on anobject. For example, a water wave moves energy throughwater. A sound wave moves energy through air. A radio wavecan move energy through space.

Because you can see water waves, it is helpful to use awater wave to describe waves in general. You cannot seemany other kinds of waves, such as sound waves.

A water wave does not carry water along with it. Only theenergy carried by the water wave moves forward. A duckmoves up and down as a wave passes — it does not moveforward.

There are different features of waves that help youdescribe them. You can see these features labelled on thediagram above. The dotted line represents the rest position ofthe wave. This is also called the equilibrium position. For awater wave, the rest position of the wave is where the waterwould be if it were still. ●✔

crest

trough

restposition

amplitude

amplitude

wavelength

wavelength

Identify DetailsAs you skim the section, useone colour to highlight thetext that talks about parts ofa wave. Use another colourto highlight other facts aboutwaves.

Section

4.1Summary

◆✏ Mark the Text

●✔ Reading Check

1. What is the rest position ofa water wave?

___________________

___________________

___________________

BC Science 8 CH04 11/5/06 11:45 AM Page 50

© 2006 McGraw-Hill Ryerson Limited Section 4.1 Properties of Waves • MHR 51

Name Date

The features of a wave are listed below.

◆ crest: the highest point of a wave

◆ trough: the lowest point of a wave

◆ wavelength: the distance from one point on a wave to thesame point on the next wave, such as from crest to crestor from trough to trough. A wave with a long wavelengthcarries less energy than a wave with a short wavelength.

◆ amplitude: the height of a wave crest from its restposition. Amplitude is also the depth of a wave trough, asmeasured from its rest position. A wave with a largeamplitude carries more energy than a wave with a smallamplitude.

How many times does a wave repeat in a period oftime?

Another important way to describe a wave is by its frequency.You may have already heard the term frequency used todescribe radio stations or music. The frequency of a wave isthe number of times it repeats in a given period of time. Arepetition of a wave is also called an oscillation or vibration.One vibration occurs over one wavelength.

Frequency is measured in hertz. Hertz (Hz) means cyclesper second.

When the wavelength is short, the frequency is high.When the wavelength is long, the frequency is low. ●✔

What are the different types of waves?

You have read that sound travels by sound waves. Sound cantravel through air, water, and even solid walls. The matter awave travels through is called a medium. The medium canbe a solid, liquid, or gas. For example, the medium of a waterwave is water.

Not all waves need a medium. For example, visible lightwaves and radio waves can travel through space where thereis no matter.

continued

Section

4.1Summary


2. How is the frequency of awave measured?

___________________

___________________

___________________



Use with textbook pages 134–136.

Features of a waveUse the vocabulary words in the box below to label the parts of a wave.

On the line beside each term, describe the wave feature.

6. amplitude ___________________________________________________________________

_____________________________________________________________________________

7. crest ________________________________________________________________________

_____________________________________________________________________________

8. trough ______________________________________________________________________

_____________________________________________________________________________

9. wavelength __________________________________________________________________

_____________________________________________________________________________

10. rest position _________________________________________________________________

_____________________________________________________________________________

Name Date VocabularySection 4.1

1.

2.

3.

4.

5.

Vocabulary

amplitudecresttrough

wavelengthrest position




Characteristics of wavesUse the information in the graphs to answer the questions.

1. How long is the wavelength of the wave below? _____________________________

2. How large is the amplitude of the wave below? ______________________________

3. Which wave below has the smaller amplitude, A or B? _____

4. Which wave carries more energy, A or B? _____

5. What is the same for waves X and Y below: amplitude, wavelength, or frequency?__________________________________

6. Which wave has a greater frequency, X or Y? _____

7. Which wave has a longer wavelength, X or Y? _____

2

1

0

–1

–2

1 5 62 3 74 1 5 62 3 74

2

1

0

–1

–2

wave X wave Y

2

1

0

–1

–2

1 2 3 4

2

1

0

–1

–2

1 2 3 4

wave A wave B

2

1

0

–1

–2

1 2 3 4 5 6 7metres metres

Name Date

AnalyzingInformationSection 4.1



True or false?Read the statements given below. If the statement is true, write “T” on the line infront of the sentence. If it is false, write “F,” and then rewrite the statement so it istrue.

1. ______ Waves transfer matter forward.

_____________________________________________________________________________

2. ______ Energy is the capacity to apply a push or pull to an object.

_____________________________________________________________________________

_____________________________________________________________________________

3. ______ A trough is the highest point in a wave.

_____________________________________________________________________________

4. ______ The wavelength is the distance from crest to trough.

_____________________________________________________________________________

5. ______ The amplitude of a wave is the height of a wave crest or the depth of a wavetrough from the rest position.

_____________________________________________________________________________

_____________________________________________________________________________

6. ______ The larger the amplitude, the less energy is transported by the wave.

_____________________________________________________________________________

_____________________________________________________________________________

7. ______ Amplitude is the number of motions that occur in a given time.

_____________________________________________________________________________

_____________________________________________________________________________

8. ______ Frequency is measured in units called hertz.

_____________________________________________________________________________

9. ______ The wavelength of a wave increases as frequency increases.

_____________________________________________________________________________

_____________________________________________________________________________


Name Date ComprehensionSection 4.1

BC Science 8 CH04 11/5/06 11:45 AM 4


Name DateAssessmentSection 4.1


Properties of waves

Circle the letter of the best answer.

6. What happens when the amplitude of awave becomes smaller?

A. the frequency increases

B. the wavelength decreases

C. the height of the crests increases

D. the amount of energy that the wavecarries decreases

7. Which of the following is not a way tomeasure wavelength?

A. the distance from crest to crest

B. the distance from trough to trough

C. the distance from the top of a crest to thebottom of a trough

D. the distance covered by one completecrest plus one complete trough

8. Which of the following statements is true?

A. The wavelength of a wave increases asthe frequency increases.

B. The wavelength of a wave increases asthe frequency decreases.

C. The wavelength of a wave decreases asthe frequency decreases.

D. The wavelength of a wave decreases asthe frequency stays the same.

Use the following diagrams to answerquestions 9 and 10.

9. Wave X has a higher frequency than Wave Y.

A. The statement is supported by the thediagrams.

B. The statement is not supported by thediagrams.

C. You cannot tell by looking at thediagrams.

10. Which statement is correct?

A. Amplitude and wavelength are the samefor both waves.

B. Amplitude is the same for both waves.

C. Wavelength is the same for both waves.

D. Neither amplitude nor wavelength is thesame for both waves.

Match each Term on the left with the bestDescriptor on the right. Each Descriptor may be

used only once.

Term Descriptor

1. ______ crest2. ______ trough3. ______ amplitude4. ______ frequency5. ______ wavelength

A. height of crest from restposition

B. a movement that carriesenergy through matter orspace

C. the lowest point of a waveD. trough to troughE. the highest point of a waveF. vibrations per second

distance travelled in 1 s

Wave X Wave Y

distance travelled in 1 s

rest position

2 m

5 m 5 m

2 m


56 MHR • Section 4.2 Properties of Visible Light © 2006 McGraw-Hill Ryerson Limited

Properties of Visible LightTextbook pages 144–151

Before You ReadOn the lines below, list five sources of light. One example is a light bulb.

_______________________________________________________________________________________

_______________________________________________________________________________________

Name Date

What is visible light?

Scientists explain light using several models. One of thesemodels is the wave model of light. In this model, light is awave that travels through empty space. Like the waves thatyou learned about in section 4.1, light waves move energyfrom one place to another. Visible light is light that you cansee. Visible light includes all the colours of the rainbow.

How do prisms affect light?

In the 17th century, English scientist Sir Isaac Newton foundthat white light, such as sunlight, is made up of light ofdifferent colours. The different colours are caused by lightwaves of different wavelengths.

How did Newton split the white light? He shone itthrough a prism. A prism is made of a clear solid, such asglass. You can see its shape in the diagram above. The lightwas split because a wave bends when it moves from onemedium to another. This bending of a wave at the borderbetween one medium and another is called refraction. Whenlight enters a prism, the medium changes from air to glass. ●✔

Light waves of different wavelengths refract at differentangles. That is why the waves separate when they exit theprism. As the diagram shows, when you place a second prismnear the first, you can cause the separated light to combine,forming white light again.

Section

4.2Summary

After you have read this section, create a quiz question for each paragraph.After you have written thequiz questions, be sure toanswer them.

◆? Create a Quiz

spectrum of visible light

prisms

white light

white light


1. What is refraction?

___________________

___________________

___________________


© 2006 McGraw-Hill Ryerson Limited Section 4.2 Properties of Visible Light • MHR 57

Name Date

What are the colours of visible light?

Visible light is made up of a range of colours. People oftenput these colours into seven categories. The categories are:red, orange, yellow, green, blue, indigo, and violet. Differentcolours are light waves of different wavelengths. Red has thelongest wavelength: around 700 nm (nanometres). Violet hasthe shortest wavelength: around 400 nm. The other colourshave wavelengths between these two.

The seven colour categories of visible light are togetherknown as the visible spectrum. The seven colour categoriesare sometimes abbreviated in the form of a person’s name:ROY G BIV (Red, Orange, Yellow, Green, Blue, Indigo, andViolet).

Why do objects appear coloured?

Reflection occurs when a light wave strikes an object andbounces off. Different materials absorb and reflect differentwavelengths of light. You see only the reflected wavelengths.A red ball looks red because it absorbs all wavelengths ofvisible light except for those around 700 nm. A black shirtlooks black because it absorbs all the colours.

Objects appear black in the dark because they do notproduce their own light. The colours you see come from othersources of light, such as the Sun or a light bulb. ●✔

How do colours of light combine?

You only need three colours of light, such as red, green, andblue, to produce all the colours of the rainbow. These threecolours are called the additive primary colours of light.

If you shine red, green, and blue light together, theyproduce white light. Adding two of these colours of light willproduce a secondary colour of light as shown below.

primary colours of light secondary colours of light• blue light + green light = cyan light• green light + red light = yellow light• blue light + red light = magenta light

continued

Section

4.2Summary


2. Why does a red ball lookblack in the dark?

___________________

___________________

___________________




Facts about visible lightAnswer the questions below.

1. When white light is refracted through a prism, different colours emerge. Where do thedifferent colours come from?

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

2. Explain why all colours refract at different angles.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

3. When does light refract or bend?

_____________________________________________________________________________

_____________________________________________________________________________

4. Which colour in the visible spectrum has the longest wavelength?

_____________________________________________________________________________

5. Which colour in the visible spectrum has the shortest wavelength?

_____________________________________________________________________________

6. Explain how you can cause light separated by a prism to combine.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

7. Which has a higher frequency, yellow light or blue light?

_____________________________________________________________________________

8. Why does a violet dress appear to be violet in sunlight?

_____________________________________________________________________________

_____________________________________________________________________________

9. List three colours that can combine to produce all the colours of the rainbow.

_____________________________________________________________________________



60 MHR • Section 4.2 Properties of Visible Light © 2006 McGraw-Hill Ryerson Limited


Visible light

Use the terms in the vocabulary box to fill in the blanks. Use each term only once.You will not need to use every term.

1. The ____________________________________ describes light travelling as a wave.

2. ____________________________________ is light that you can see.

3. The bending or changing direction of a wave as it passes from one material toanother is called ______________________________________________.

4. White light is made up of waves having different _________________________________and ____________________________________________.

5. Sir Isaac Newton demonstrated that ____________________________________ is aproperty of visible light.

6. A ____________________________________ refracts light into different colours.

7. When passed through a second prism, the _________________________________ light is combined to form white light once again.

8. The seven colour categories of visible light are together known as the visible____________________________________.

9. You can remember the order of the seven colours of the rainbow by using thisabbreviation: ____________________________________.

10. A fire engine appears to be red because the colour red is____________________________________.

11. A black shirt appears black because all colours are____________________________________.

Name Date

ClozeActivity

Section 4.2

Vocabulary

absorbedamplitudecolourfrequenciesprismreflectedreflectionrefracted

refractionROY G BIVspectrumvisible lightwave model of lightwavelengthswhite light




Use with textbook pages 144-149.

Properties of visiblelight


7. Which of the following statements is true?

A. White light has no colours in it.

B. Sunlight emits only yellow light.

C. There are six colours in the rainbow.

D. You can see the colours of the rainbowwhen sunlight is refracted.

8. Which of the following statements isincorrect?

A. Light travels like a wave.

B. Colour is a property of visible light.

C. A prism splits light into a spectrum.

D. Each colour in the visible spectrumrefracts at the same angle.

9. Which of the following correctly places thecolours in order of shortest wavelength tolongest wavelength?

10. Which of the following colours has thelowest frequency?

A. blue

B. indigo

C. orange

D. yellow

11. Why does a blue car appear to be blue inthe sunlight?

A. The car reflects all the colours of thevisible spectrum.

B. The car absorbs the colour blue andreflects colours other than blue.

C. The car refracts the colour blue andreflects colours other than blue.

D. The car reflects the colour blue andabsorbs colours other than blue.

12. Why does the print on this page appear tobe black?

A. The print reflects all the colours.

B. The print absorbs all the colours.

C. The print is made up of all the primarycolours.

D. The print is made up of all the secondarycolours.

Shortest wavelength ⎯⎯→ Longest wavelength

A. red green violet

B. violet green red

C. green red violet

D. violet red green


used only once.

Term Descriptor

1. ______ light2. ______ spectrum3. ______ reflection4. ______ refraction5. ______ visible light6. ______ wave

model of light

A. explains how lightbehaves like a wave

B. light we can seeC. a range of colours or

frequencies of visiblelight

D. occurs when a lightwave is absorbed by anobject

E. occurs when a lightwave bounces off anobject

F. bending of light wave asit passes from one material to another

G. wave that travelsthrough space


62 MHR • Section 4.3 Light and the Electromagnetic Spectrum © 2006 McGraw-Hill Ryerson Limited

Light and the Electromagnetic SpectrumTextbook pages 152–165

Before You ReadChoose a technology that uses invisible waves, such as microwave ovens, radio, X rays,or wireless Internet connections. Explain how the technology affects your life.

_______________________________________________________________________________________

_______________________________________________________________________________________

Name Date

What is the electromagnetic spectrum?

Light that you can see is an example of a form of energycalled radiant energy. This energy spreads out, or radiates,from its source in all directions. The Sun is a source ofradiant energy. Radiant energy is not just visible light. TheSun and other sources of energy also give off energy inwaves you cannot see. These waves transport energy by thevibration of electrical and magnetic fields. That is why thesewaves, including visible light waves, are known aselectromagnetic radiation.

The spectrum of electromagnetic radiation is known as theelectromagnetic spectrum. The electromagnetic spectrumincludes radio waves, which can have wavelengths that arekilometres long. It also includes gamma rays, which can havewavelengths smaller than an atom. The spectrum includes allthe electromagnetic waves in between. ●✔

Section

4.3Summary

Identify DetailsHighlight the names of different types of waves asyou read them. Say theirnames aloud. Underline thenames of technologies thatdepend on the waves.

◆✏ Mark the Text


1. What larger spectrum ofwaves is the visible spectrum part of?

___________________

___________________

___________________

X raysvisible light

radio waves infrared waves ultraviolet waves gamma rays

microwaves

increasing frequencydecreasing wavelength


© 2006 McGraw-Hill Ryerson Limited Section 4.3 Light and the Electromagnetic Spectrum • MHR 63

Name Date

What waves have wavelengths longer than visiblelight?

◆ Radio waves have the longest wavelengths in theelectromagnetic spectrum. Radio waves are used forbroadcasting radio and television signals. Radio waves arealso used in medicine. They allow us to see inside ourbodies using magnetic resonance imaging (MRI). Microwaves are a type of radio wave. As well as beingused in microwave ovens, microwaves are also used tocommunicate with satellites.

◆ Infrared waves have wavelengths longer than red light inthe visible spectrum. Heat lamps used by restaurants tokeep food warm emit invisible infrared waves as well asred light. Infrared waves are also used in remote controlsfor televisions and for reading CD-ROMs. Infrared wavesare also called heat radiation. ●✔

What waves have wavelengths shorter than visiblelight?

◆ Ultraviolet waves have wavelengths shorter than violetlight in the visible spectrum. Your body needs to absorbultraviolet waves to make vitamin D. Too much exposureto ultraviolet waves, though, can result in sunburns andskin cancer. Ultraviolet waves are used to kill bacteriafound in food, water, and on medical tools.

◆ X rays have shorter wavelengths and higher energy andfrequencies than ultraviolet waves. X rays are used tophotograph bones and teeth, to check the inside ofbaggage at airports, and to check jet engines and othermachines for damage.

◆ Gamma rays have the shortest wavelengths, the highestenergy, and the highest frequency of the electromagneticspectrum. Gamma rays are used in radiation therapy tokill cancer cells.

continued

Section

4.3Summary


2. What are three uses forinfrared waves?

___________________

___________________

___________________





True or false?Read the statements given below. If the statement is true, write “T” on the line infront of the statement. If it is false, write “F” and rewrite the statement to make ittrue.

1. ______ Radiant energy spreads out from its source in all directions.

_____________________________________________________________________________

_____________________________________________________________________________

2. ______ Electromagnetic radiation includes only visible light waves.

_____________________________________________________________________________

_____________________________________________________________________________

3. ______ Microwaves are a type of infrared wave.

_____________________________________________________________________________

_____________________________________________________________________________

4. ______ X rays have more energy than gamma rays.

_____________________________________________________________________________

_____________________________________________________________________________

5. ______ Radio waves, microwaves, and ultraviolet waves all have longer wavelengthsthan visible light.

_____________________________________________________________________________

_____________________________________________________________________________

6. ______ Both X rays and gamma rays have higher frequencies than ultraviolet rays.

_____________________________________________________________________________

_____________________________________________________________________________

7. ______ Communicating with satellites is an application of gamma rays.

_____________________________________________________________________________

_____________________________________________________________________________

8. ______ The Sun radiates both visible energy and invisible energy.

_____________________________________________________________________________

_____________________________________________________________________________


66 MHR • Section 4.3 Light and the Electromagnetic Spectrum © 2006 McGraw-Hill Ryerson Limited


More than meets the eye

Use the terms in the vocabulary box to fill in the blanks. Use each term only once.

1. The ____________________________________ represents the different forms ofelectromagnetic radiation.

2. Light is classified as ____________________________________ because electricaland magnetic fields vibrate in a light wave.

3. ____________________________________ is energy that travels by radiation. Anexample of this is light.

4. Heat radiation, also known as ____________________________________, cannotbe seen by your eyes but can be felt by your skin.

5. Microwaves are one type of ____________________________________ .

6. ____________________________________ can be used to communicate withsatellites.

7. Because ____________________________________ have the highest energy of allelectromagnetic radiation, they are the most damaging to human tissue.

8. Compared to all other types of electromagnetic radiation, radio waves have thelowest ____________________________________.

9. An overexposure to ____________________________________ can result insunburns and skin cancer.

Name Date

ClozeActivity

Section 4.3

Vocabulary

electromagnetic radiationelectromagnetic spectrumfrequencygamma raysinfrared wavesmicrowaves

radiant energyradio wavesultraviolet raysvisible lightwavelengthX rays





Visible light and theelectromagnetic spectrum


Use the following diagram of theelectromagnetic spectrum to answerquestions 5 to 10.

5. Which of the following types of radiationhas the highest frequency?

A. visible light

B. infrared light

C. AM radio waves

D. gamma radiation

6. Which of the following is generallyassociated with radio waves?

A. visible radiation

B. high-energy waves

C. high-frequency waves

D. long-wavelength waves

7. Which of the following types of radiationgives off the lowest amount of energy?

A. X rays

B. visible light

C. microwaves

D. gamma rays

8. Which of the following correctly placesthese electromagnetic waves in order fromshortest wavelength to longest wavelength?

A. visible light, radio waves, ultravioletlight, infrared radiation

B. radio waves, visible light, infraredradiation, ultraviolet light

C. ultraviolet light, visible light, infraredradiation, radio waves

D. ultraviolet light, infrared radiation, radiowaves, visible light

9. Which of the following has a higherfrequency than visible light?

A. infrared waves

B. X rays

C. microwaves

D. radio waves

10. How does the frequency of electromagneticradiation change as wavelength of theradiation decreases?

A. it increases

B. it decreases

C. it stays the same

D. it increases and then decreases


used only once.

Term Descriptor

1. ______ X rays2. ______ microwaves3. ______ gamma rays4. ______ radio waves

A. used to heat up left-overpizza

B. used to broadcast television

C. used by computers toread CD-ROMS

D. used in radiation therapyto kill cancer cells

E. used by dentists to take apicture of your teeth

long wavelengthlow frequencylow energy

aircraft andshipping bands

AMradio

shortwave radio

TV and FM radio

microwaves Radar

infraredlight

ultravioletlight

X rays gamma-rays

The Electromagnetic Spectrum short wavelengthhigh frequency

high energy

visi

ble


68 MHR • Section 5.1 The Ray Model of Light © 2006 McGraw-Hill Ryerson Limited

The Ray Model of LightTextbook pages 168–181

Before You ReadLight reflects from white paper and also from a mirror. Why can you see yourself in amirror but not in the sheet of paper? Record your ideas on the lines below.

_______________________________________________________________________________________

_______________________________________________________________________________________

Name Date

What can happen when light strikes different materials?

The ray model of light shows the direction of light as itmoves in a straight line. You can use this model to show whathappens when light strikes different materials. Three thingscan happen when light strikes a material.1. The light may be transmitted (pass straight through it).

2. The light may be reflected (bounce off it).

3. The light may be absorbed (become “trapped” in it).

Each of these three outcomes affects what you see when lightstrikes a material. ●✔

◆ If all or most of the light is transmitted, the material istransparent. Clear glass, air, and water are transparentbecause light passes through them.

◆ If all or most of the light is absorbed or reflected so thatnone of the light passes through, the material is opaque.A book, a metal can, and a wall are opaque because theyblock light from passing through them.

◆ If only some of the light is transmitted, and that light isscattered in all directions, the material is translucent.Waxed paper, clouds, and lampshades are translucentbecause they scatter the light that passes through them.

What happens when light reflects from a plane mirror?

When light reflects from a plane (flat) mirror, the rays of lightbounce off the mirror in a regular pattern. The angle of anincoming light ray is the angle of incidence (i). The angle ofthe reflected ray is the angle of reflection (r).

Section

5.1Summary

Create a QuizAfter you have read this section, create a five-question quiz based on what you have learned. Thenanswer your quiz questions.


1. What three things canhappen to light when itstrikes a material?

___________________

___________________

___________________


© 2006 McGraw-Hill Ryerson Limited Section 5.1 The Ray Model of Light • MHR 69

Name Date

The angle of incidence is always equal to the angle ofreflection. You can see yourself in a mirror because of thisregular reflecting pattern.

Even when light reflects from a rough, uneven surface, theangle of incidence of the light rays is still equal to the angleof reflection of the light rays. However, on a rough surface,each light ray reflects at a different angle. In other words,there is no regular pattern of reflection. That is why youcannot see yourself in a sheet of paper. ●✔

How is the angle of refraction different from theangle of reflection?

Light rays can refract, or bend. They refract when they movefrom one material into another, such as from water into air.The normal is an imaginary line that passes through bothmaterials at a right angle. If light rays slow down as theyrefract, they bend toward the normal. If light rays speed up asthey refract, they bend away from the normal. The angle ofrefraction (R) is the angle of the ray of light that comes outof the boundary between the two materials, measuredbetween the refracted ray and the normal.

continued

Section

5.1Summary


2. How does the angle ofincidence relate to theangle of reflection?

___________________

___________________

___________________

normal

angle ofreflection

angle ofincidence

r i

incident rayreflected ray

reflecting surface

normal normal

air

boundary

waterrefracted rayR

R refractedray


Light Can Reflect and Refract

Use the terms in the vocabulary box above to fill in the blanks. You will not need touse all the terms.

1. In the _____________________________________________________, light is described

as a ray that travels in a straight path.

2. When light strikes _____________________________ materials, it passes through them.

3. When light strikes _____________________________ materials, it passes through them,

but it is scattered from its straight path.

4. _______________________________ materials do not allow light to pass through them.

5. The angle of reflection is equal to the angle of __________________________________.

6. Light rays bounce off a ______________________________ with a regular reflecting

pattern.

7. The angle of ______________________________________________________ is the angle

of a light ray that comes out of the boundary between two materials.

8. The angle of refraction is measured between the _________________________________

and the normal.

Vocabulary

incidencematerialnormalplane mirrorray model of lightreflected rayreflection

refracted rayrefractionsheet of papertransparenttranslucentopaque


Gary

Text Box

© 2006 McGraw-Hill Ryerson Limited Section 5.1 The Ray Model of Light • MHR 73



The ray model of light


5. Which of the following statementsdescribes a property of light according tothe ray model of light?

A. Light travels like waves.

B. Light travels in a straight line.

C. Light is made up of different colours.

D. Light has characteristics like frequencyand wavelength.

6. If the angle of incidence is 50°, what is theangle of reflection?

A. 5°

B. 25°

C. 50°

D. 100°

Use the following diagram to answerquestions 7 and 8.

7. Which of the following is a translucentsurface?

A. surface X

B. surface Y

C. surface Z

D. surface X and surface Z

8. Which of the following surfaces allow allthe light rays to pass through?

A. surface X

B. surface Y

C. surface Z

D. surface X and surface Z

9. Which of the following correctly describesopaque objects?

A. I and III only

B. II and III only

C. III and IV only

D. I, II, and III

surfaceY

surfaceZ

surfaceX

I. they can absorb all the light

II. they can reflect all the light

III. they do not allow light to pass throughthem

IV. they transmit all light


used only once.

Term Descriptor

1. ______ normal2. ______ angle of

refraction3. ______ angle of

reflection4. ______ angle of

incidence

A. equal to the angle ofreflection

B. measured between therefracted ray and the normal

C. angle of reflected rayD. imaginary line that passes

through materials at rightangle

E. the surface that reflects


bc science 8 ch04 - · pdf fileuse with textbook pages 134–138. true or false? read the...

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