name: period:ferrophysics.weebly.com/uploads/1/0/2/2/102257044/light... · 2020. 3. 16. · name:...

Name: _____________________________________________________

Period: __________________

Name: ____________________

Unit IX: Light Regents Physics

Unit Syllabus and Portfolio Directions Objectives: Track your progress towards meeting the unit objectives.

LightLWAV.A1 I can explain and analyze the speed of light including the

speed in different transparent materials. LWAV.A2 I can explain and analyze the reflection of waves, including

Diffuse and regular reflections. LWAV.B1 I can explain and analyze the refraction of waves, including

use of Snell’s Law. LWAV.B2 I can describe total internal reflection and explain its

application. LWAV.C1 I understand the principle of diffraction and can identify its

effects qualitatively.

LWAV.C2 I understand and can answer questions about the Electromagnetic Spectrum.

LWAV.D1 I understand and can answer questions about white light and how it applies to a prism

LWAV.D2 I understand and can answer questions about light phenomena including polarization

Rating Completion Rating Completion

_____ ____Unit Syllabus and Progress Checklists

_____ ____Vocabulary

_____ ____Snell’s law lab ( LWAV.B1)

_____ ____ pg 168-169 72-87 (LWAV.A1, LWAV.B1)

_____ ____ pg170 88-101 (LWAV.A1, LWAV.B1)

_____ ____pg 171 102-116 (LWAV.A1,) (LWAV.B1,B2,C1,C2,D1,D2)

_____ Refraction work sheet #1(LWAV.A1,A2,B1,B2)

_____ ____Critical angle (LWAV.B2)

_____ ___Mixed review ((LWAV.A1,A2,B1,B2,C1,C2,D1,D2)

Light quiz Grade ________

Name: ______________ Light vocabulary

Date: _________

Absolute index of refraction-

angle of incidence-

angle of reflection-

angle of refraction-

antinode-

incident ray-

interference-

law of reflection-

1

medium-

ray-

reflected ray-

refracted ray-

reflection-

refraction-

2

1. Electromagnetic Waves

a. The E-field changes → the B-field changes → the ________changes → the ________changes …

i. In the pictures the lines represent how strong the fields are.

b. All electromagnetic waves move at the speed of__________________(c).

i. c = 3.00 x 108 , (3.00 x 108 = 671,000,000 mph)

ii. Nothing can move ____________ than the speed of light.

c. Photon: the ________________ possible bit (quanta) of anelectromagnetic wave

d. The energy (E) of electromagnetic waves depends onfrequency.

i. The unit for energy (E) is the ______________________

e. E = h f ← this formula gives the energy (E) of 1__________________

f. Planck’s constant:

3

2. Visible light

a. Emitted by anything hotter than 700°C.

b. Part of the electromagnetic spectrum

i. ROY G. BIV—a good way to remember the colors of the rainbow

c. Light is absorbed and radiated in quantum units (the smallest possible bits) called photons.

3. Wave Formula

a. v = f λ

b. In a vacuum v = c (3 x 108 m/s) ---> c = f λ

Example 1: Blue light has a frequency of 6.3 x 1014 Hz. What is the wavelength of this color of light?

Example 2: An E/M wave has a frequency of 2.0 x 1021 Hz? What is the wavelength of this wave? Using your ref tab identify what type of wave it is and check your answer.

4

Name: __________________________ Date: ___________________________

Electromagnetic Waves

1. (1 pt) The energy of an electromagnetic wave depends on _________________.

2. (1 pt) What is the speed of all electromagnetic waves? ____________________

3. Fill in the blanks.

4. (2 pts) The alternating current (AC) in the wall oscillates at 60 Hz. AC current moves at thespeed of light. What is the wavelength of the waves of electricity?

5. (2 pts) Draw an electromagnetic wave.

6. (2 pts) How does changing an electric field make an electromagnetic field?

7. Pretend Jenaye’s bus is a wave.a. (2 pts) What is the speed of Jenaye’s bus if it has a frequency of 4.7 Hz and a

wavelength of 11 m?

b. (2 pts) How much energy does Jenaye’s bus have?

Jet speed = 0 m/s (1 pt) Speed of light =

Jet speed = 900 m/s (1 pt) Speed of light =

Parked Jet

Flying Jet

light

light

5

8. (2 pts) Jerrell decides to take up surfing. He rides a wave with a wavelength of 5.63 m at a speed of 4.2 m/s. What is the frequency of the wave?

9. Blue light has a frequency of 7.5 x 1014 Hz.a. (2 pts) What is the wavelength of blue light?

b. (2 pts) The quantum theory of light says that light is radiated and absorbed in littlebits called photons. How much energy does a photon of blue light have?

10. The wavelength of red light is 7.9 x 10-7m.a. (2 pts) What is the frequency of red light?

b. (2 pts) How much energy does a photon (the smallest bit) of red light have?

11. (2 pts) Marcus tunes his radio to 92 Q which has a frequency of 92,300 Hz. What is thewavelength of 92 Q?

12. (2 pts) What is the principle of superposition? Hint: look in the glossary or the index.

13. (2 pts) Can electromagnetic waves interfere with each other? Explain.

14. (1 pt) Who was the first American to win a Nobel Prize in science?

6

2. Light Ray: the path of an extremely _______________ beam of light

a. all visible objects emit or _____________ light rays in all possible directions

b. people only see objects when light rays from those object enter our ___________________

3. Reflection: light changes directions when it bounces off __________________

a. ________________ reflection: light bounces off molecularly rough surfaces randomly

b. _________________ reflection: light bounces off mirrored(molecularly smooth) surfaces in parallel beams

i. incident angle (θi): the angle that the light ____________ the surface

ii. reflection angle (θr): the angle that the light _____________ off the surface

iii. Law of Reflection: the incident angle equals the reflected angle

θi= θr

4

5.

7

Name: Period:

Waves-Reflection

APlusPhysics: Waves-Reflection Page 1WAV.C1

1. The diagram below represents a light ray striking theboundary between air and glass.

What would be the angle between this light ray and its reflected ray?1. 30°2. 60°3. 120°4. 150°

2. The diagram below represents a view from aboveof a tank of water in which parallel wave fronts aretraveling toward a barrier.

Which arrow represents the direction of travel for the wave fronts after being reflected from the bar-rier?1. A2. B3. C4. D

3. A sonar wave is reflected from the ocean floor. Forwhich angles of incidence do the wave’s angle ofreflection equal its angle of incidence?1. angles less than 45°, only2. an angle of 45°, only3. angles greater than 45°, only4. all angles of incidence

4. Two plane mirrors are positioned perpendicular toeach other as shown. A ray of monochromatic redlight is incident on mirror 1 at an angle of 55°. Thisray is reflected from mirror 1 and then strikes mirror2.

Determine the angle at which the ray is incident on mirror 2 and label the angle on the diagram (in degrees). On the diagram, use a protractor and straightedge to draw the ray of light as it is reflected from mirror 2.

5. The diagram below represents a light ray reflectingfrom a plane mirror.

The angle of reflection for the light ray is1. 25°2. 35°3. 50°4. 65°

8

Name: Period:

Waves-Reflection

APlusPhysics: Waves-Reflection Page 2WAV.C1

Base your answers to the following questions on the information and diagram below:

In the diagram, a light ray, R, strikes the boundary of air and water.

6. Using a protractor, determine the angle of incidence.

7. Using a protractor and straightedge, draw the reflected ray on the diagram above.

Total Internal Reflection - the wave cannot pass through a boundary an is entirely reflected

9

E/M Waves

1. Radio waves and gamma raystraveling in space have the same

a. frequencyb. wavelengthc. periodd. speed

2. Which pair of terms best describeslight waves traveling from the Sunto Earth?

a. electromagnetic andtransverse

b. electromagnetic andlongitudinal

c. mechanical and transversed. mechanical and longitudinal

3. Which wavelength is in the infraredrange of the electromagneticspectrum?

a. 100 nmb. 100 mmc. 100 md. 100 μm

4. Orange light has a frequency of 5.0 ×1014 hertz in a vacuum. What is thewavelength of this light?

a. 1.5 × 1023 mb. 1.7 × 106 mc. 6.0 × 10-7 md. 2.0 × 10-15 m

5. Compared to the period of a wave ofred light the period of a wave ofgreen light is

a. lessb. greaterc. the same

6. An electromagnetic AM-band radiowave could have a wavelength of

a. 0.005 mb. 5 mc. 500 md. 5,000,000 m

7. Radio waves are propagatedthrough the interaction of

a. nuclear and electric fieldsb. electric and magnetic fieldsc. gravitational and magnetic

fieldsd. gravitational and electric

fields

8. How much time does it take lightfrom a flash camera to reach asubject 6.0 meters across a room?

a. 5.0 × 10-9 sb. 2.0 × 10-8 sc. 5.0 × 10-8 sd. 2.0 × 10-7 s

9. Which color of light has awavelength of 5.0×10-7 meter in air?

a. blueb. greenc. oranged. violet

10. In a vacuum, all electromagneticwaves have the same

a. speedb. phasec. frequencyd. wavelength

10

4. Refraction: the ____________________________that occurs when a lightwave passes through a boundary between ____________________

a. Index of Refraction: a measure of optical ______________.

i. Water has a ____________optical density than air.ii. See ref tab for a list

iii. represented with n (n1, n2,…. etc)

b. When light goes from an area of ________________ optical density (n1) to anarea of _______________ optical density (n2)…

i. The light slows downii. The frequency ____________________.iii. The wavelength decreases.iv. The light bends toward the ______________ from the normal (see

picture)

c. When light goes from an area of _________________ optical density (n1)to an area of _____________ optical density (n2)…

i. The light speeds upii. The frequency _________________.iii. The wavelength increases.iv. The light bends ___________________ from the normal (see

picture)

6.

11

d. Index of refraction - proportional to the speed of light in a vacuumand the speed of light in the medium n

Example 1: Calculate the speed of yellow light (5.09 x 1014 Hz) in Lucite

e. When light refracts there is change in speed and wavelength. The formulabelow describes the relationship between these quantities.

Example 2: A wave with a frequency of 5.09 x 1014 Hz enters diamond from air. What is the wavelength in a diamond?

12

Name: Period:

Waves-Refraction

APlusPhysics: Waves-Refraction Page 1WAV.C2

1. In which way does blue light change as it travels from diamond into crown glass?1. Its frequency decreases.2. Its frequency increases.3. Its speed decreases.4. Its speed increases.

Base your answers to questions 2 through 4 on the infor-mation and diagram below.

A monochromatic light ray (f=5.09 × 1014 Hz) traveling in air is incident on the surface of a rectangular block of Lucite (n=1.50).

2. Measure the angle of incidence for the light ray to the nearest degree.

3. Calculate the angle of refraction of the light ray when it enters the Lucite block. {Show all work, including the equation and substitution with units.]

4. What is the angle of refraction of the light ray as it emerges from the Lucite block back into the air?

5. A change in the speed of a wave as it enters a new medium produces a change in1. frequency2. period3. wavelength4. phase

6. The diagram below represents a ray of monochro-matic light (f=5.09 × 1014 Hz) passing from medium X (n=1.46) into fused quartz (n=1.46).

Which path will the ray follow in the quartz?1. A2. B3. C4. D

7. A straight glass rod appears to bend when placed in a beaker of water, as shown in the diagram below.

What is the best explanation for this phenomenon?1. The water is warmer than the air.2. Light travels faster in water than in air.3. Light is reflected at the air-water interface.4. Light is refracted as it crosses the air-water

interface.

13

Name: Period:

Waves-Refraction


Base your answers to questions 8 through 10 on the information and diagram below.

A ray of monochromatic light having a frequency of 5.09 × 1014 hertz is incident on an interface of air and corn oil (n=1.47) at an angle of 35° as shown. The ray is transmitted through parallel layers of corn oil and glycerol (n=1.47) and is then reflected from the surface of a plane mirror, located below and parallel to the glycerol layer. The ray then emerges from the corn oil back into the air at point P.

8. Calculate the angle of refraction of the light ray as it enters the corn oil from air. [Show all work, including the equation and the substitution with units.

9. Explain why the ray does not bend at the corn oil-glycerol interface.

10. On the diagram, use a protractor and straightedge to construct the refracted ray representing the light emerging at point P into air.

11. Which diagram best represents the behavior of a ray of monochromatic light in air incident on a block of crown glass (n=1.52)?

14

Name: Period:

Waves-Refraction


Base your answers to questions 12 through 14 on the information below.

A ray of monochromatic light (f= 5.09 × 1014 Hz) passes through air and a rectangular transparent block, as shown in the diagram below.

12. Using a protractor, determine the angle of incidence of the light ray as it enters the transparent block from air.

13. Calculate the absolute index of refraction for the medium of the transparent block. [Show all work, including the equation and substitution with units.]

14. Calculate the speed of the light ray in the transparent block. [Show all work, including the equation and substi-tution with units.]

15. A wave generator having a constant frequency produces parallel wave fronts in a tank of water of two different depths. The diagram below represents the wave fronts in the deep water.

As the wave travels from the deep water into the shallow water, the speed of the waves decreases. On the diagram at right, use a straightedge to draw at least three lines to represent the wave fronts, with appropriate spacing, in the shallow water.

15

Name: Period:

Waves-Refraction


16. A laser beam is directed at the surface of a smooth, calm pond as represented in the diagram below.

Which organisms could be illuminated by the laser light?1. the bird and the fish2. the bird and the seaweed3. the crab and the seaweed4. the crab and the fish


A ray of light (f= 5.09 × 1014 Hz) is incident on the boundary between air and an unknown material X at an angle of incidence of 55°, as shown. The absolute index of refraction of material X is 1.66.

17. Determine the speed of this ray of light in material X.

18. Calculate the angle of refraction of the ray of light in material X.

19. On the diagram above, use a straightedge and protractor to draw the refracted ray of light in material X.

16

Name: Period:

Waves-Refraction


20. A ray of monochromatic light (f= 5.09 × 1014 Hz)passes from water through flint glass (n=1.66) andinto medium X, as shown below.

The absolute index of refraction of medium X is1. less than 1.332. greater than 1.33 and less than 1.523. greater than 1.52 and less than 1.664. equal to 1.66

21. A beam of light travels through medium X with aspeed of 1.80 × 108 meters per second. Calculate theabsolute index of refraction of medium X. [Show allwork, including the equation and substitution withunits.]

22. What happens to the speed and frequency of a lightray when it passes from air into water?1. The speed decreases and the frequency increases.2. The speed decreases and the frequency remains

the same.3. The speed increases and the frequency increases.4. The speed increases and the frequency remains

the same.

23. A ray of monochromatic light (f= 5.09 × 1014 Hz) inair is incident at an angle of 30° on a boundary withcorn oil (n=1.47). What is the angle of refraction, tothe nearest degree, for this light ray in the corn oil?1. 6°2. 20°3. 30°4. 47°


A ray of light passes from air into a block of transparent material X as shown in the diagram below.

24. Measure the angles of incidence and refraction tothe nearest degree for this light ray at the air intomaterial X boundary.

θi= θr=

25. Calculate the absolute index of refraction of mate-rial X. [Show all work, including the equation andsubstitution with units.]

26. The refracted light ray is reflected from the materialX–air boundary at point P. Using a protractor andstraightedge, on the diagram in your answer booklet,draw the reflected ray from point P.

27. If the speed of a wave doubles as it passes from shal-low water into deeper water, its wavelength will be1. unchanged2. doubled3. halved4. quadrupled

17

Name: Period:

Waves-Refraction


Base your answers to questions 28 and 29 on the information and diagram below.

A ray of monochromatic light (f= 5.09 × 1014 Hz) passes from air into Lucite at an angle of incidence of 30°.

28. Calculate the angle of refraction in the Lucite. [Show all work, including the equation and substitution with units.]

29. Using a protractor and straightedge, on the diagram draw the refracted ray in the Lucite.

30. Which ray diagram best represents the phenomenon of refraction?

31. The diagram at right represents straight wave fronts passing from deep water into shallow water, with a change in speed and direction.

Which phenomenon is illustrated in the diagram?1. reflection2. refraction3. diffraction4. interference

18

Name: Period:

Waves-Refraction



A light ray with a frequency of 5.09 × 1014 hertz travel-ing in air is incident at an angle of 40° on an air-water interface as shown. At the interface, part of the ray is refracted as it enters the water and part of the ray isreflected from the interface.

32. Calculate the angle of refraction of the light ray as it enters the water. [Show all work, including the equation and substitution with units.]

33. On the diagram above, using a protractor and straightedge, draw the refracted ray. Label this ray “Refracted ray.”

34. On the diagram above, using a protractor and straightedge, draw the reflected ray. Label this ray “Reflected ray.”

35. An electromagnetic wave of wavelength 5.89 × 10-7 meter traveling through air is incident on an inter-face with corn oil (n=1.47). Calculate the wave-length of the EM wave in corn oil.

36. The speed of light in a piece of plastic is 2.00 × 108 meters per second. What is the absolute index of refraction of this plastic?1. 1.002. 0.673. 1.334. 1.50

37. A ray of monochromatic light is incident on an air-sodium chloride (n=1.54) boundary as shown in the diagram below. At the boundary, part of the ray is reflected back into the air and part is refracted as it enters the sodium chloride.

Compared to the ray’s angle of refraction in the sodium chloride, the ray’s angle of reflection in the air is1. smaller2. larger3. the same

38. The diagram below shows a ray of light passing from air into glass at an angle of incidence of 0°.

Which statement best describes the speed and direc-tion of the light ray as it passes into the glass?1. Only speed changes.2. Only direction changes.3. Both speed and direction change.4. Neither speed nor direction changes.

19

Name: Period:

Waves-Refraction


Base your answers to questions 39 through 42 on the diagram below, which represents a ray of monochromatic light (5.09 × 1014 Hz) in air incident on flint glass (n=1.66).

39. Determine the angle of incidence of the light ray in air.

40. Calculate the angle of refraction of the light ray in the flint glass. [Show all work, including the equation and substitution with units.]

41. Using a protractor and straightedge, draw the refracted ray on the diagram.

42. What happens to the light from the incident ray that is not refracted or absorbed?

43. The diagram below represents a wave.

What is the speed of the wave if its frequency is 8.0 hertz?1. 48 m/s2. 16 m/s3. 3.2 m/s4. 1.6 m/s

44. What is the wavelength of a light ray with fre-quency 5.09 × 1014 hertz as it travels through Lucite (n=1.50)?1. 3.93 × 10-7 m2. 5.89 × 10-7 m3. 3.39 × 1014 m4. 7.64 × 1014 m

45. The speed of light (f=5.09 × 1014 Hz) in a trans-parent material is 0.75 times its speed in air. The absolute index of refraction of the material is ap-proximately1. 0.752. 1.33. 2.34. 4.0

20

Name: Period:

Waves-Refraction


46. A light ray traveling in air enters a second medium and its speed slows to 1.71 × 108 meters per sec-ond. What is the absolute index of refraction of the second medium?1. 1.002. 0.5703. 1.754. 1.94

Base your answers to questions 47 and 48 on the dia-gram below, which represents a light ray traveling from air to Lucite (n=1.50) to medium Y and back into air.

47. The sine of angle θx is1. 0.3332. 0.5003. 0.7074. 0.886

48. Light travels slowest in1. air, only2. Lucite, only3. medium Y, only4. air, Lucite, and medium Y

49. Which quantity is equivalent to the product of the absolute index of refraction of water and the speed of light in water?1. wavelength of light in a vacuum2. frequency of light in water3. sine of the angle of incidence4. speed of light in a vacuum

50. What is the speed of light (f=5.09 × 1014 Hz) in flint glass?1. 1.81 × 108 m/s2. 1.97 × 108 m/s3. 3.00 × 108 m/s4. 4.98 × 108 m/s

51. What happens to the frequency and the speed of an electromagnetic wave as it passes from air into glass?1. The frequency decreases and the speed increases.2. The frequency increases and the speed decreases.3. The frequency remains the same and the speed

increases.4. The frequency remains the same and the speed

decreases.

52. When a light wave enters a new medium and is refracted, there must be a change in the light wave’s1. color2. frequency3. period4. speed

53. As a sound wave passes from water, where the speed is 1.49 × 103 meters per second, into air, the wave’s speed1. decreases and its frequency remains the same2. increases and its frequency remains the same3. remains the same and its frequency decreases4. remains the same and its frequency increases

54. In a certain material, a beam of monochromatic light (f=5.09 × 1014 Hz) has a speed of 2.25 × 108 meters per second. The material could be1. crown glass (n=1.52)2. flint glass (n=1.66)3. glycerol (n=1.47)4. water (n=1.33)

21

E/M Waves HW- Part 2 11) Calculate the wavelength in a vacuum of a radio wave having a frequency of 2.2 × 106 hertz. [Show all work, including the equation and substitution with units.] {10 points}

Base your answers to questions 12 and 13 on the information and diagram below: A 1.50 × 10–6-meter-long segment of an electromagnetic wave having a frequency of 6.00 × 1014 hertz is represented below.

12) On the diagram above, mark two points on the wave that are in phase with each other. Label each point

with the letter P. {5 points}

13) Which type of electromagnetic wave does the segment in the diagram represent?

14) An FM radio station broadcasts its signal at a frequency of 9.15 × 107 hertz. Determine the wavelength of the signal in air. [Show all work, including the equation and substitution with units.]

22

a. The wavelength must be greater than the size of the opening.

i. If the wavelength is 10 cm and the opening is 5 cm, willdiffraction occur?

ii. If the wavelength is 10 cm and the opening is 20 cm, willdiffraction occur?

iii. Why don’t we see diffraction of light through the classroomdoor?

b. The smaller the opening, the _____________ the diffraction.

c. The longer the wavelength, the ____________the diffraction.

d. Thomas Young’s Double-Slit Experiment - famous experiment whichutilized diffraction to prove light has properties of waves.

8. Polarization -

7. Diffraction - bending of waves around __________________, or the spreading of waves as they pass through an opening,

23

Name: Period:

Waves-Diffraction

APlusPhysics: Waves-DiffractionPage 194 WAV.D1

1. A wave of constant wavelength diffracts as it passes through an opening in a barrier. As the size of the opening is increased, the diffraction effects1. decrease2. increase3. remain the same

2. The diagram below shows a series of wave fronts approaching an opening in a barrier. Point P is located on the opposite side of the barrier.

The wave fronts reach point P as a result of1. resonance2. refraction3. reflection4. diffraction

3. Which wave phenomenon makes it possible for a player to hear the sound from a referee’s whistle in an open field even when standing behind the referee?1. diffraction2. Doppler effect3. reflection4. refraction

4. A wave is diffracted as it passes through an opening in a barrier. The amount of diffraction that the wave undergoes depends on both the1. amplitude and frequency of the incident wave2. wavelength and speed of the incident wave3. wavelength of the incident wave and the size of

the opening4. amplitude of the incident wave and the size of

the opening

5. The diagram below shows a plane wave passing through a small opening in a barrier.

On the diagram above, sketch four wave fronts after they have passed through the barrier.

6. Which diagram best represents the shape and direction of a series of wave fronts after they have passed through a small opening in a barrier?

24

Name: Period:

Waves-Diffraction

APlusPhysics: Waves-Diffraction Page 195WAV.D1

7. Parallel wave fronts incident on an opening in a barrier are diffracted. For which combination of wavelength and size of opening will diffraction ef-fects be greatest?1. short wavelength and narrow opening2. short wavelength and wide opening3. long wavelength and narrow opening4. long wavelength and wide opening

8. A beam of monochromatic light approaches a barrier having four openings, A, B, C, and D, of different sizes as shown below.

Which opening will cause the greatest diffraction?1. A2. B3. C4. D

9. Radio waves diffract around buildings more than light waves do because, compared to light waves, radio waves1. move faster2. move slower3. have a higher frequency4. have a longer wavelength

10. Waves pass through a 10-centimeter opening in a barrier without being diffracted. This observation provides evidence that the wavelength of the waves is1. much shorter than 10 cm2. equal to 10 cm3. longer than 10 cm, but shorter than 20 cm4. longer than 20 cm.

11. The spreading of a wave into the region behind an obstruction is called1. diffraction2. absorption3. reflection4. refraction

12. The diagram below shows a series of straight wave fronts produced in a shallow tank of wa-ter approaching a small opening in a barrier.

Which diagram represents the appearance of the wave fronts after passing through the opening in the barrier?

25

Name: Period:

Waves-Diffraction

APlusPhysics: Waves-DiffractionPage 196 WAV.D1

13. The diagram below shows wave fronts approaching an opening in a barrier. The size of the opening is approximately equal to one-half the wavelength of the waves. On the diagram, draw the shape of at least three of the wave fronts after they have passed through this opening.

26

Light Review Sheet

Electromagnetic Radiation –

Related Formulas/Ref Tab Section:

Interference-

This proves that light is a _________

Reflection-


Refraction –


Example 1) A ray of blue light (wavelength = 4.92 x 10-8 m) travels through air and strikes glass at an angle of 35 degrees. What is the angle of refraction?

Example 2) What is the wavelength of that light in glass?

27

Base your answers to questions 1 through 3 on the information below. A ray of monochromatic light (f= 5.09 × 1014 Hz) passes through air and a rectangular transparent block, as shown in the diagram below.

1. Using a protractor, determine the angle of incidence of the light ray as it enters the transparent block from

air. 2. Calculate the absolute index of refraction for the medium of the transparent block. [Show all work,

including the equation and substitution with units.]

3. Calculate the speed of the light ray in the transparent block. [Show all work, including the equation and

substitution with units.]

Base your answers to questions 4 through 6 on the information and diagram below. A ray of light (f= 5.09 × 1014 Hz) is incident on the boundary between air and an unknown material X at an angle of incidence of 55°, as shown. The absolute index of refraction of material X is 1.66.

4. Determine the speed of this ray of light in material X. 28

5. Calculate the angle of refraction of the ray of light in material X. 6. On the diagram above, use a straightedge and protractor to draw the refracted ray of light in material X. 7. A ray of monochromatic light (f= 5.09 × 1014 Hz) in air is incident at an angle of 30° on a boundary with corn oil (n=1.47). What is the angle of refraction, to the nearest degree, for this light ray in the corn oil? 1. 6° 2. 20° 3. 30° 4. 47° 8. The diagram at right represents straight wave fronts passing from deep water into shallow water, with a change in speed and direction. Which phenomenon is illustrated in the diagram?

9. An electromagnetic wave of wavelength 5.89 × 10-7 meter traveling through air is incident on an interface with corn oil (n=1.47). Calculate the wavelength of the EM wave in corn oil. 10. The speed of light (f=5.09 × 1014 Hz) in a transparent material is 0.75 times its speed in air. The absolute

index of refraction of the material is approximately 1. 0.75 2. 1.3 3. 2.3 4. 4.0

1. reflection 2. refraction 3. diffraction 4. interference .

29

Light

45

Light

A. Light is an ___________________________ and a ___________________________wave.

B. It is a small portion of the electromagnetic spectrum.C. The speed of light is _________________________________________

D. It is found by _________________ (same as __________________).

E. Nothing moves faster than light. Sorry, science fiction lovers!

Light Terms

1. _________: A straight line that indicates the __________________ of wave travel.

2. _____________________: A ray that originates in one medium and ___________________________________________ of a second medium.

3. ______________________: A ray that ______________ off of the surface of a secondmedium.

4. ________________: A ___________________ line that is drawn to the reflectionsurface.

5. Angle of Incidence (θi): The angle between the _________________ and the____________________________.

6. Angle of Reflection (θr): The angle between the __________________ and the______________________.

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Light Phenomena

A. ___________________: The bouncing of light waves off of an object or the boundary between two different media.

B. Law of reflection: Angle of Incidence is equal to Angle of Reflection ________________.C. _________________________:

i. When a beam of _____________ light waves (rays) strikes a ____________________ and all of the reflected rays are also ___________________.

ii. The image produced is a mirror image.D. _________________________:

i. When a beam of _________________ light waves (rays) strikes a ______________ (irregular) surface, the reflected rays are scattered in all directions, they are _______ ______________________.

E. Refraction:i. The ____________________________ as they move from one medium to another.ii. The change in ______________ is due to a change in _________________.iii. If the wave enters a medium that has a ___________________________________

than the medium in which it is traveling, the wave will bend ______________ the normal line.

iv. If the wave enters a medium that has a _____________________________than the medium in which it is traveling, the wave will bend ____________ from the normal.

F. Index of Refraction:i. The ratio of the speed of light in a vacuum to the speed of light in any given

medium.ii. It is given by:

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G. Snell’s Lawi. Snell’s Law is the relationship between the angles of incidence and refraction

when a light ray passes from one medium to another.ii. It is given by:

H. Critical Angle

I. Total Internal Reflectioni. The phenomena produced by the reflection of a light ray whose angle of

incidence is ______________ than the critical angle.ii. This only occurs when light is trying to move from a _________ index

medium to a _________ index medium.iii. No refraction of the light occurs, only ______________________.

J. Dispersive and Non-Dispersive Mediai. ____________________ Medium – a medium in which waves of

____________________ ___________________________ all travel at___________________ ____________________. For example, light(polychromatic) in a glass prism.

ii. ___________________________ Medium – A medium in which waves of allfrequencies travel at the _________________________. For example, soundwaves (polyphonic) in air, or light waves

i. The angle of incidence that produces an angle of refraction of 90° when a lightray passes into a lower index of refraction from a higher index of refraction.

ii. It is given by:

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K. Diffractioni. The _____________________ of light behind a barrier.ii. It is explained by Huygens principle.iii. It also occurs when light _______________________________ of a

barrier.iv. It produces an _____________________ pattern of light and dark regions

based on constructive and destructive interference.

__________________________ – Light from two or more sources that have a constant phase relationship.

L. Polarization1. A ray of light in which all of the vibrations (waves) are in

the_________________________________ is said to be polarized light.2. Polarization is the process of producing polarized light.3. Only ______________________________ waves may be polarized.

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