Light Calculations Find the v of each of

Light Calculations

Find the v of each of these. n = c/v Material n v Vacuum 1. 0000 3. 00 E 8 m/s Air 1. 0003 3. 00 E 8 m/s Ice 1. 31 2. 29 E 8 m/s Water 1. 333 2. 25 E 8 m/s Ethyl Alcohol 1. 36 2. 21 E 8 m/s Crown Glass 1. 52 1. 97 E 8 m/s Zircon 1. 923 1. 56 E 8 m/s Diamond 2. 417 1. 24 E 8 m/s

Calculating Ray Diagrams ni sinΘi =nrsinΘr 1. 0003 x sin 35 = nr sin 30 1. 0003 x 0. 574 0. 5 nr = 1. 15 = nr 0. 5 ni = 1. 0003 Θi ? Θr

Calculating Ray Diagrams ni sinΘi =nrsinΘr sinΘ = 0. 456 1. 333 x sin 20 = 1. 0003 sin Θ 1. 333 x 0. 342 = 1. 0003 sin Θ 1. 0003 * To get Θ alone you need to multiply the opposite side by sin -1 Θ = sin Θi -1 * 0. 456 ni = 1. 333 Θ = 27. 1 Θr o nr = 1. 0003

Practice • How far will light travel in 12 seconds? t = 12 s d=? v = d/t v = 3 E 8 m/s d = vt 3 E 8 m/s x 12 s = 3. 60 E 9 m • How long does it take light to travel 123456789 m? t = d/v t = ? v = 3 E 8 m/s E-1 s d = 123456789 m 123456789 m / 3 E 8 m/s = 4. 12 • How fast (m/s) does a beam of light travel if it takes 5 s to travel 1. 50 E 6 km? t = 5 s v = ? v = d/t =1. 50 E 9 m/5 s d = 1. 50 E 6 km 1. 50 E 9 m v = 3. 00 E 8 m/s

Θi = ? Air Glass Θr =100

Θi =450 water n=? What medium Θr =230

Θi = 48. 70 n=? What medium? ice Θr = 350

air Θi = 780 zircon Θr = ? θ = 30. 6 O

1. 0003 x sinθ = 1. 52 sin 10 θ = 15. 3 0 Θi = ? sinθ = 0. 264/1. 0003 θ = sin-10. 264 Air Glass Θr =100

1. 333 x sin 45 = n sin 23 0. 943/. 391 = n n = 2. 41 diamond Θi =450 water n=? What medium Θr =230

n x sin 48. 7 = 1. 31 sin 35 n = 0. 751/0. 751 n = 1. 00 vacuum/air Θi = 48. 70 n=? What medium? ice Θr = 350

1. 0003 x sin 78 = 1. 923 sinθ = 0. 978/1. 923 = sinθ θ = sin-10. 509 θ = 30. 6 O air Θi = 780 zircon Θr = ? θ = 30. 6 O