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Unformatted text preview: Solution for Practice Test 10 for Test 4 Solution to Practice Test Problem 10.1(Time Delay Iraq to Fayetteville) Problem: There was a noticable time delay in the war reports from the middle east. The distance from Fayetteville to Iraq is exactly 11 , 208 , 000m . (This should tell you if the delay is lightspeed delay). How long does it take an electromagnetic signal to reach Fayetteville from Iraq? Select One of the Following: (a) 26s (b) . 000008s (c) . 0012s (d-Answer) . 037s (e) Toby. Solution (d): t = d v = 1 . 12 10 7 m 3 . 10 8 m s = 0 . 037s Total Points for Problem: 3 Points Solution to Practice Test Problem 10.2(Magnification of Flat Diving Mask) Problem: Water has an index of refraction of 4 / 3 . A diving mask has a flat lens. Calculate the magnification and image location of a fish at arms length ( 2 / 3m ) formed by a flat diving mask. Select One of the Following: (a) s =- 2 / 3m , m = 1 . (b-Answer) s =- 1 / 2m , m = 1 . (c) s =- 1 / 2m , m = 3 / 4 . (d) s =- 8 / 9m , m = 1 . (e) Toby Solution (b): n i s + n t s = n t- n i r where r = , so n i s + n t s = 0 s =- n t s n i =- (1) 2 3 m 4 3 =- 1 2 m m =- n i s n t s =- ( 4 3 )(- 1 2 ) (1)( 2 3 ) = 1 1 Total Points for Problem: 3 Points Solution to Practice Test Problem 10.3(Curvature for Equal Object/Image Distances) Problem: Now we want to design a diving mask that produces an image of the fish at the location where the fish is, that is the object and image distance of the fish is the same (up to a sign). The fish is 2 / 3m from the mask and the index of refraction of water is still 4 / 3 . Compute the radius of curvature of the glass in the mask. Select whether the mask bends in toward the diver or out toward the water. Select One of the Following: (a) | r | = 3m inward. (b-Answer) | r | = 2 / 3m inward. (c) | r | = 3m outward. (d) | r | = 2 / 3m outward. (e) Toby Solution (b): n i s + n t s = n t- n i r For the situation given s = 2 / 3m =- s n i s + n t- s = n t- n i r So r =- s =- 2 / 3m So the center of curvature is on the fish side of the mask. The mask bends inward toward the diver. Total Points for Problem: 3 Points Solution to Practice Test Problem 10.4(Frequency of Light in Material) Problem: A light source has wavelength 450nm in vacuum. Calculate the frequency of the light source in a material with index of refraction 4 / 3 . Select One of the Following: (a-Answer) 6 . 7 10 14 s 1 (b) 8 . 9 10 14 s 1 (c) 6 . 7 10 5 s 1 (d) 5 10 14 s 1 (e) Toby....
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This note was uploaded on 05/04/2008 for the course PHYS 2074 taught by Professor Stewart during the Spring '08 term at Arkansas.
- Spring '08