PHYS-115(3) (Kaldon-16406) Name ______________________________________WMU - Winter 2001Exam 3 - 100,000 points Book Title __________________________________________Section: 3a 3b 3c 3d A to F G to M N to S T to Z 03/28/2001•Rev.4State Any Assumptions You Need To Make -- Show All Work -- Circle Any Final AnswersUse Your Time Wisely - Work on What You Can - Be Sure to Write Down EquationsBOLDFACE Variables Are Vectors - Feel Free to Ask Any QuestionsTrack 7 • Any Colour You Like PINK FLOYD—THE DARK SIDE OF THE MOON (50,000 points)1.) (a) For a particular kind of glass, n2 = 1.55. If light came in from the air side, n1 = 1.00, at an angle q1 =45°, then find the angle q2.nnnnnn112 22112211121100 4515527 1sin sinsinsinsinsinsin.sin..qqqqqq===FHGIKJ=°FHGIKJ=°--(b) If you could see the Pink Floyd The Dark Side of the Moon CD cover in color, the white ray at the left splitsin colored rays (ROYGBIV) with red at the top and violet at the bottom. This is due to the phenomena calleddispersion. If the index of refraction for red light is nred = 1.5500 and violet light is it nviolet = 1.5656, explainwhether the order of colors as shown on the CD cover is correct or inverted.Violet light has the larger index of refraction, so at the air-to-glass interface, the angle in the glass is LESS than the redlight (and so comes in lower in the diagram). So when itarrives at the edge of the glass, it comes it at a larger angleto the normal, so it gets bent MORE than red light in air (andit is still lower in the diagram).So the CD cover is CORRECT.(c) Given the information in (a) and (b), briefly explain whether the picture on the CD cover is accurate orflawed. You may wish to do a couple of calculations to prove your point. Do not write long paragraphs – makeshort comments that are easy to read. Use the Worksheet on Page 5 if you need more room.RED qcnn=FHGIKJ=FHGIKJ=°--sin sin...112110015540 2 VIOLETqc=FHGIKJ=°-sin...11001565639 7We can find the Critical Angle going from glass back to air, andby eyeballing the picture, the angles appear less that these.And the angles in air are all larger than their counterparts inthe glass, so the CD cover is ACCURATE.Physics 115 / Exam 3 Winter 2001 Page 2(d) Before there were Compact Disc players, we had things called“albums” and “LP records”. People I knew in the dorm atNorthwestern University would play The Dark Side of the Moon ontheir huge speakers at 300 W. With the speakers blasting that loud,find the current in the speaker wire at 12.0 V.A.C. and find how muchcurrent that represents coming from the 120. V.A.C. electrical outlet.PIVIPVWVAIWVA=== ===30012 025 0300120250......(e) With the primary side of a transformer at 120. V.A.C. and thesecondary side at 12.0 V.A.C., find the number of windings on the primary side if there are 100. windings on thesecondary side.NV NVNNVVVVturns11 2 21221100 12 012010=== =....bgb gbgTime to Get Serious About Starship and Keanu Reeves? (50,000 points)2.) Sirius – the Dog Star – is 8.60 light years from Earth. (a) How many meters is this?dctm s years days yearhour day hourm==´=´2 998 10 8 60 365 2524 36008136 10816./. .//sec/.chbgb gbgb gSir·i·us (sĭr¹ē-əs) nounA star in the constellation Canis Major, thebrightest star in the sky, approximately 8.6light-years distant from Earth. Also calledDog Star, Sothis.[Latin Sīrius, from Greek Seirios, fromseirios, burning.]Dogstar / Happy EndingPhysics 115 / Exam 3 Winter 2001 Page 3(b) The Jefferson Starship is heading to Sirius at a speed of 0.860 that of light. How many years will they thinkthe trip takes?(This is the Classical Physics answer – when we do Special Relativity, you’ll see this answer gets complicated.)dvttdvmms===´´=8136 100 860 2 998 10315 600 000168... /,,secch OR tdvLYcyears== =860086010 00...(c) Show that Music Impresario Dick Clark sees the same amountof time pass on the Earth whether you use the distance as seen fromEarth or convert the time as seen on the Jefferson Starship.We haven’t done Special Relativity Yet.Jefferson Airplane / Freedom at Point Zero . . . .(d) The light from Sirius shines on a lens with a focal length f = 10,000. mm = 10.0 m. Although the star ishuge, it is very far away and so the in-focus image will still be that of a point. Where is the image, q, of Siriuslocated? If you did not get an answer to (a), use p = ¥ .But of course this is true – parallel rays from the starconverge on the focal point on the right!(e) This lens contains an anti-reflection coating ( ncoating = 1.38 ) on glass ( nglass = 1.55 ) in air (nair = 1.00 ). Ifthe coating is 200. nm thick, for what wavelength of light is this an anti-reflection coating in air?We haven’t done Physical Optics Yet.111111110 0fpq qfqqf