YF_ISM_33

YF_ISM_33 - THE NATURE AND PROPAGATION OF LIGHT 33 33.1...

This preview shows pages 1–3. Sign up to view the full content.

33-1 T HE N ATURE AND P ROPAGATION OF L IGHT 33.1. I DENTIFY : For reflection, r a θ θ = . S ET U P : The desired path of the ray is sketched in Figure 33.1. E XECUTE : 14.0 cm tan 11.5 cm φ = , so 50.6 φ = ° . 90 39.4 r θ φ = = ° ° and 39.4 r a θ θ = = ° . E VALUATE : The angle of incidence is measured from the normal to the surface. Figure 33.1 33.2 I DENTIFY : For reflection, r a θ θ = . S ET U P : The angles of incidence and reflection at each reflection are shown in Figure 33.2. For the rays to be perpendicular when they cross, 90 α = ° . E XECUTE : (a) 90 θ φ + = ° and 90 β φ + = ° , so β θ = . 90 2 α β + = ° and 180 2 α θ = ° . (b) 1 1 2 2 (180 ) (180 90 ) 45 θ α = = = ° ° ° ° . E VALUATE : As 0 θ ° , 180 α ° . This corresponds to the incident and reflected rays traveling in nearly the same direction. As 90 θ ° , 0 α ° . This corresponds to the incident and reflected rays traveling in nearly opposite directions. Figure 33.2 33

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
33-2 Chapter 33 33.3. I DENTIFY and S ET U P : Use Eqs.(33.1) and (33.5) to calculate v and . λ E XECUTE : (a) 8 8 2.998 10 m/s so 2.04 10 m/s 1.47 c c n v v n × = = = = × (b) 0 650 nm 442 nm 1.47 n λ λ = = = E VALUATE : Light is slower in the liquid than in vacuum. By , v f λ = when v is smaller, λ is smaller. 33.4. I DENTIFY : In air, 0 c f λ = . In glass, 0 n λ λ = . S ET U P : 8 3.00 10 m/s c = × E XECUTE : (a) 8 0 14 3.00 10 m/s 517 nm 5.80 10 Hz c f λ × = = = × (b) 0 517 nm 340 nm 1.52 n λ λ = = = E VALUATE : In glass the light travels slower than in vacuum and the wavelength is smaller. 33.5. I DENTIFY : c n v = . 0 n λ λ = , where 0 λ is the wavelength in vacuum. S ET U P : 8 3.00 10 m/s c = × . n for air is only slightly larger than unity. E XECUTE : (a) 8 8 3.00 10 m/s 1.54. 1.94 10 m/s c n v × = = = × (b) 7 7 0 (1.54)(3.55 10 m) 5.47 10 m. n λ λ = = × = × E VALUATE : In quartz the speed is lower and the wavelength is smaller than in air. 33.6. I DENTIFY : 0 n λ λ = . S ET U P : From Table 33.1, water 1.333 n = and benzene 1.501 n = . E XECUTE : (a) water water benzene benzene 0 n n λ λ λ = = . water benzene water benzene 1.333 (438 nm) 389 nm 1.501 n n λ λ = = = . (b) 0 water water (438 nm)(1.333) 584 nm n λ λ = = = E VALUATE : λ is smallest in benzene, since n is largest for benzene. 33.7. I DENTIFY : Apply Eqs.(33.2) and (33.4) to calculate and . r b θ θ The angles in these equations are measured with respect to the normal, not the surface. (a) S ET U P : The incident, reflected and refracted rays are shown in Figure 33.7. E XECUTE : 42.5 r a θ θ = = ° The reflected ray makes an angle of 90.0 47.5 r θ ° − = ° with the surface of the glass. Figure 33.7 (b) sin sin , a a b b n n θ θ = where the angles are measured from the normal to the interface. sin (1.00)(sin42.5 ) sin 0.4070 1.66 a a b b n n θ θ ° = = = 24.0 b θ = ° The refracted ray makes an angle of 90.0 66.0 b θ ° − = ° with the surface of the glass. E VALUATE : The light is bent toward the normal when the light enters the material of larger refractive index. 33.8. I DENTIFY : Use the distance and time to find the speed of light in the plastic.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern