7. Refractive index (n) n = speed of light in a vacuum speed of light in the medium Q ~ What is n for a) air b) water 225 000 000 Water 299 900 000 Air 300 000 000 Vacuum Speed of light (m/s) Medium
8. Snell’s law i r n = sin i sin r medium i medium r “ Angle of refraction depends on the refractive index”
9. Snell’s law n = sin i sin r Q ~ If the medium is water (n = 1.33) and angle i is 30 , what is angle r ? r = 22 n = sin i sin r 1.33 = sin 30 sin r sin r = sin 30 1.33 sin r = 0.5 = 0.38 1.33
10. Snell’s law n = sin i sin r Q ~ In another medium, if i is 30 and r is 12 , what is n? Q ~ If the medium is water (n = 1.33) and angle i is 40 , what is angle r ?