Nelson Physics 12 Chapter 7.3 Solutions

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Chapter 9 Review, pages 494â€" .Chapter 9 Review, pages 494â€"499...

Chapter 9 Review, pages 494â€" .Chapter 9 Review, pages 494â€"499 ... travels through the air because

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Copyright 2012 Nelson Education Ltd. Chapter 9: Waves and Light 9-2

Chapter 9 Review, pages 494499 Knowledge 1. (d) 2. (b) 3. (a) 4. (b) 5. (a) 6. (b) 7. (d) 8. (b) 9. (a) 10. (b) 11. (a) 12. (d) 13. False. The angle of incidence is measured between the incoming ray and the normal to the reflecting surface. 14. False. The amplitude of a water wave is the vertical distance from the top of a crest to the rest position of the wave or from the bottom of the trough to the rest position of the wave. 15. True 16. False. The dependence of the speed of light on wavelength is called dispersion. 17. False. The index of refraction is likely different for red and blue light in the same material. 18. False. When light enters a medium of higher index of refraction, the angle of incidence is greater than the angle of refraction. 19. True 20. False. As a light wave refracts from air into glass, the only quantity to remain constant is the frequency. 21. False. The symbol c is used in reference to the speed of light in a vacuum. 22. True 23. False. Diffraction of waves decreases as the width of the slit increases. 24. True 25. False. Light waves diffract the same amount as water waves. 26. False. Newtons corpuscular theory of light did have an explanation for the small amount of diffraction displayed by visible light that could be observed with the techniques of his time. 27. True 28. True 29. False. For angles of less than 10, the sine and tangent of the angle are approximately equal. 30. False. An advantage of fibre optic technology is that large amounts of information can be transmitted with few losses over large distances. 31. (a) (vii) (b) (v) (c) (i) (d) (vi) (e) (ii) (f) (iv) (g) (iii)
Copyright 2012 Nelson Education Ltd. Chapter 9: Waves and Light 9-3

Understanding 32. Answers may vary. Sample answer:

n = cv

[n2 sin!2]=cv2

"

#$

%

&'

oppositehypotenuse

"

#$

%

&'

=

ms

"

#$$

%

&''

mm

"

#$$

%

&''

ms

"

#$$

%

&''

[n2 sin!2]= 1

The quantity 2 2sinn has no units. It is dimensionless. 33. (a) Answers may vary. Sample answers: To see laser light, the wavelength used in the laser must fall within the range of wavelengths that our eyes can detect. Laser light is invisible when it travels through the air because the density of air molecules is very low, and the light does not reflect from enough of the molecules for us to see it. When laser light hits a white screen, the light reflects from the screen to your eye and you can see it. (b) Answers may vary. Sample answers: To see the laser light, one could introduce smoke, fog, dry ice vapour, or chalk dust into the air. These substances have enough small particles for some of the laser light to reflect to your eye. 34. Answers may vary. Sample answer: When parallel light rays reflect off smooth water, all the rays have the same angle of incidence and the same angle of reflection. The reflected light remains a reasonably well-defined beam. When parallel light rays reflect off rough water, the light rays are reflected in a variety of directions and no longer look like a beam of light.

35. Sample answer: As white light enters a prism, the light is refracted. Since the index of refraction of the prism is slightly different for the different colours that compose white light, each colour is refracted at a slightly different angle. The red light refracts the least, and the violet light refracts the most. When the light exits the prism, the light refracts again. Again, the red light refracts less than the blue light. Since the light enters and exits the prism through faces that are not parallel, the colours are spread out more and more by each refraction. The final result is the visible spectrum on the far side of the prism.
Copyright 2012 Nelson Education Ltd. Chapter 9: Waves and Light 9-4

36. Sample answer: Newton thought of light as a stream of small particles, and Huygens thought of light as a series of wave fronts. Newtons light particles changed direction because of their mass and the effect of gravity, and Huygens wave fronts spread out between and around objects. Newtons light particles bend toward the normal when moving into a medium with higher wave speed, and Huygens wave fronts bend toward the normal when moving into a medium with lower wave speed. According to Newtons particle theory, light does not need a medium in which to travel, which is true. Additional information: To Newton, the mass of the light particle was responsible for colour; to Huygens, the wavelength of light was responsible for colour. 37. Sample answer: In Youngs double-slit experiment, light from a single source passed through two slits and made a pattern on a screen on the other side. The pattern consisted of many white, coloured, and dark lines called fringes. When a coloured filter was placed in front of the light, Young observed a pattern of evenly spaced coloured and dark fringes. Interpreting the bright and dark fringes as maxima and minima of a wave pattern was consistent with similar patterns observed in water waves. A particle model of light would predict that there should be two fuzzy streaks of light on the screen as the particles passed individually through one slit or the other and landed on the screen. The observations in Youngs experiment disagreed completely with particle model predictions and was in complete agreement with a wave model for light. 38. Answers may vary. Sample answer: Advantages: Fibre optic cables provide reliable, long-distance transmission of large amounts of data. Since they have no moving parts, they can withstand a lot of rough treatment and bad weather. Disadvantages: Installation of fibre optic cable everywhere on Earth is expensive. If the fibre optic cables ever do need to be fixed, it is extremely difficult to splice them without leaving a scar, which destroys the cables total internal reflection ability. Analysis and Application 39. Given: 7 2650 nm 6.5 10 m; 1.0 cm 1.0 10 m = = = = d Required: N, number of wavelengths in d

Analysis: = dN

Solution:

2

7

4

1.0 10 m6.5 10 m1.5 10

=

=

=

dN

N

Statement: About 1.5 104, or 15 000, wavelengths of red light would fit across a fingernail. 40. Given: f = 88.7 MHz = 8.87 107 Hz; v = 3.0 108 m/s Required: Analysis: Rearrange the universal wave equation, =v f , to solve for wavelength;

=

=

v fvf
Copyright 2012 Nelson Education Ltd. Chapter 9: Waves and Light 9-5

Solution:

83.0 10 m/ s

=

=

vf

78.87 10 Hz3.4 m =

Statement: The wavelength of the radio waves is 3.4 m. 41. Given: D = 4.4 ly; c = 3.0 108 m/s Required: D , in metres Analysis: Use = d v t to determine how far light travels in one year. This gives the conversion between light years and metres. Then multiply d by 4.4 ly to calculate D in metres. Solution:

8 m(3.0 10 s

=

=

d v t

)(1 y 3600 s)1 h

24 h1 d

365.25 d1 y

159.47 10 m (one extra digit carried) = d

(4.4 ly=D159.47 10 m)

1 ly

164.2 10 m= D

Statement: The distance to Alpha Centauri is 4.2 1016 m. 42. Sample answer: Pyrex and vegetable oil have almost the same index of refraction. When light passes from one medium to the other, there is little refraction. With no perceived boundary between the Pyrex and the oil, very little light is reflected and refracted. With no reflected light, we do not see the test tube. 43. Given: 12 81.1 billion kilometres 1.1 10 m; 3.0 10 m/s = = = d v Required: t

Analysis: Rearrange the definition of speed, =dvt

, to solve for time. Then convert the time to

hours; =dvt

; = dtv

Solution:

121.1 10 m

=

=

dtv

8 m3.0 10

3

s

(3.667 10 s= 1 h)3600 s

1.0 h =t

Statement: It takes 1.0 h for the message to travel from Cassini to Earth.
Copyright 2012 Nelson Education Ltd. Chapter 9: Waves and Light 9-6

44. Given: 81.51; 3.0 10 m/s= = n c Required: v

Analysis: Rearrange the equation = vnc

to solve for speed;

= cnv

; = cvn

Solution:

8

8

3.0 10 m/s1.51

2.0 10 m/s

=

=

=

cvn

v

Statement: The speed of light in Plexiglas is 2.0 108 m/s. 45. Given: 80.55 ; 3.0 10 m/s= = v c c Required: n

Analysis: = vnc

Solution:

0.551.8

=

=

=

cnvcc

n

Statement: The index of refraction of the transparent material is 1.8. 46. Given: 7Pyrex water vacuum1.47; 1.33; 5.30 10 m

= = = n n Required: Pyrex water;

Analysis: Rearrange the alternative definition of index of refraction, 12

=n , to solve for 2 ;

1

2

=n ; 12 =n

Solution: 12

vacuumPyrex

Pyrex

7

7

Pyrex

5.30 10 m1.47

3.61 10 m361 nm

=

=

=

= =

n

n

!2 =!1n

!water =!vacuumnwater

= 5.30"10#7 m

1.33= 3.98"10#7 m

!water = 398 nm

Statement: The light has a wavelength of 361 nm in Pyrex and 398 nm in water.
Copyright 2012 Nelson Education Ltd. Chapter 9: Waves and Light 9-7

47. Given: 1 1 252.0 ; 1.33; 1.46 = = =n n Required: 2 Analysis: Rearrange the equation 1 1 2 2sin sin =n n to solve for 2 ; 1 1 2 2

1 12

2

1 1 12

2

sin sinsinsin

sinsin

=

=

=

n nnn

nn

Solution: 1 1 1

22

1

2

sinsin

(1.33)sin52.0sin1.46

45.9

=

=

=

nn

Statement: The an

Midterm Review (pages 1-27)

Contralínea 494

Nov 4 Pages - Dayton Review

Futuro 494

Sept 16 Pages - Dayton Review

The Power of Art, 1995, 494 pages, Richard Lewis ... Power of Art, 1995, 494 pages, Richard Lewis, 0155003208, 9780155003200, Harcourt Brace College Publishers, 1995 DOWNLOAD http