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_, , , , Key, , Electromagnetic Waves, Example Problems, , Example 1: What is the frequency green light that has a wavelength, -1_m9 —_——, ear ae &y Seed of Wight = 3.0 xio*®, , Vt AF -;# ‘Ss constant, _— Vv. 3.0 #10" o x10 ®, FT > Sore » =[5,5 407 He |, Example 2: What is the wavelength of a microwave that has a, frequency of 4.2 X 10°-hz? 6 tye of Light; Phere he, , ya At, , Vv SX’, , A= 7 =, , 5, , , , “he Fl, , G2 nie, , Example 3: When an electromagnetic wave travels from one, medium to another its speed changes (either increases or, decreases) while its frequency stays the same., , —, of = a + a) What should happen to the wavelength of an, electromagnetic wave if its speed decreases as it goes, If F shys caste) — from air to glass?, , Vo A are directly The wave length skow/d /ncrease as weH/, , ee tonal. ——————, 7 b) Find the speed of the green light from Example 1 if, its wavelength changes to 4.2 X 107-m, , i Answer from # /, vij\f= =(W2K10° r)(s. sto?), , ce

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Example 4: Compare the properties of an x-ray and a radio signal., , a) What type of waves are these?, , Bots are elec tr magne te waves, , b) Which wave travels at the greatest speed?, , Same klad of 4 ve ao S@rmre Seed, , ¢) Which wave has the greater wavelength?, , Raclio waves Aave greater weve leng/h, , d) Which wave has the greater frequency?, , X-rays have ke greoter freguercy, , Example 5: Red light has a frequency of 4.0 X 10'*-hz., , a) Find the speed of red light in a vacuum if its wavelength is Ye HL 4, 1 wvo/lXte NES aS FAC, 75 x 10 m. co S, a | of figh ? in, , viAt =@sx0?) (4x0) 3x07 % | a ve coum,, , b) As the red light above enters glass its wavelength changes to, 5.8 X 10°7-m, but its frequency remains constant. What is the, speed of red light in this glass., , viAF = (55107) (¥10) = [232 110° %], , ¢) The index of refraction of a material is the ratio of the speed of, , light in a vacuung to the speed of light in the material. What is, the index of refraction for the glass in part b?, , V en Vatcer 3xXIV, , Vin motel LI [1,27]