This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Daniels, Matthew Quiz 4 Due: Dec 7 2006, midnight Inst: Ditmire 1 This printout should have 23 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. The due time is Central time. 001 (part 1 of 1) 10 points What is the frequency of an electromagnetic wave if it has a wavelength of 1.2 km? The speed of light is 3 10 8 m / s. Correct answer: 250000 Hz. Explanation: Let : = 1 . 2 km and c = 3 . 00 10 8 m / s . The speed is c = f f = c = 3 10 8 m / s 1 . 2 km 1 km 10 3 m = 250000 Hz . keywords: 002 (part 1 of 2) 10 points The secondorder bright fringe ( m = 2) is 4 . 45 cm from the center line. 4 . 45cm 1 . 11 m . 0307mm S 1 S 2 viewing screen Determine the wavelength of the light. Correct answer: 615 . 383 nm. Explanation: Let : y = 4 . 45 cm , L = 1 . 11 m , and d = 0 . 0307 mm , r 2 r 1 y L d S 1 S 2 = ta n 1 y L viewing screen d sin r 2 r 1 P O 6 S 2 QS 1 90 Q r 2 r 1 d S 1 S 2 = ta n 1 y L d s i n r 2 r 1 6 S 2 Q S 1 9 Q For constructive interference y bright = L d m, (1) with m = 2, y 2 = 0 . 0445 m, L = 1 . 11 m, and d = 3 . 07 10 5 m = dy 2 mL = (3 . 07 10 5 m)(0 . 0445 m) (2)(1 . 11 m) = 6 . 15383 10 7 m = 615 . 383 nm . 003 (part 2 of 2) 10 points Calculate the distance between adjacent bright fringes. Correct answer: 2 . 225 cm. Explanation: From equation (1) and the results of the first part of the problem, we get y m +1 y m = L ( m + 1) d Lm d = L d Daniels, Matthew Quiz 4 Due: Dec 7 2006, midnight Inst: Ditmire 2 = (6 . 15383 10 7 m)(1 . 11 m) (3 . 07 10 5 m) = 0 . 02225 m = 2 . 225 cm . keywords: 004 (part 1 of 1) 10 points The reflecting surfaces of two intersecting flat mirrors are at an angle of 64 , as shown in the figure. A light ray strikes the horizon tal mirror, reflects off the horizontal mirror, impinges on the raised mirror, reflects off the raised mirror, and proceeds in the righthand direction. 64 Figure is not drawn to scale. Calculate the angle . Correct answer: 52 . Explanation: Basic Concept: incident = reflected Solution: 1 2 Figure is to scale. The sum of the angles in a triangle is 180 . In the triangle on the left we have angles , 180  1 2 , and 180  2 2 , so 180 = + 180  1 2 + 180  2 2 , or 1 + 2 = 2 . (1) In the triangle on the right we have angles 1 , 2 , and . 180 = 1 + 2 + , so 1 + 2 = 180  . (2) Combining Eq. 1 and 2, we have = 180  2 = 180  2(64 ) = 52 . As a matter of interest, in the upperhalf of the figure the angles (clockwise) in the triangles from left to right are 47 , 47 , and 86 ; 94 , 26 , and 60 ; 120 , 17 , and 43 ; 137 , 17 , and 26 ; and in the lowerhalf of the figure the angles (counterclockwise) in the triangles from left...
View
Full
Document
This note was uploaded on 06/23/2008 for the course PHY 303L taught by Professor Turner during the Spring '08 term at University of Texas at Austin.
 Spring '08
 Turner

Click to edit the document details