Question

The index of refraction for fresh water is n water - 1.333. The speed of light in a vacuum is c = 3.00 times 10^8 m/s. What is the speed of light in fresh water? Write the result in terms of 108 m/s. For example if the result is 1.234*108 m/s, just enter 1.234. (keep 3 decimal places) Enter a number x108 m/s Submit (5 attempts remaining) Refraction creates Optical illusion NORMAL line (perpendicular) 2. to water The above figure shows how a scuba diver in water and his instructor on the side of the swimming pool "see" each other. This is an example of "optical illusion". The index of refraction of air nair = 1.00. "water = 1.333, 82 =24°. What is the angle 81 ? Keep 1 decimal place. Enter a number Submit (5 attempts remaining) Refraction Case 1 n air Case 2 n air 8 ne glass water water Case 1: A light ray coming from air is incident on water. n="air = 1.00.01 =32º. n3 = "water = 1.333 What is the angle 03 in water? Keep 1 decimal place. Enter a number Submit (5 attempts remaining) Case 2: A slab of glass is placed on top of water. A light ray coming from air is incident on glass and enters glass, then enters water. ng="air = 1.00. 01 =32º. n2 = "glass -1.52. n3 = "water = 1.333 What is the angle 02 in glass? Keep 2 decimal places. Enter a number Submit (5 attempts remaining) What is the angle 03 in water? Keep 1 decimal place. Enter a number Submit (5 attempts remaining) INSIGHT: compare the 03 in Case 1 and Case 2. The two rays in ng are parallel to each other.

Answer 1

A n water 3.1.333 c= 3x10 8 mis we know ne 8 =) V- 3x108 mis - = 2.250 X10 1. 333 Ang 2.250 x 108 mis Mair 2 ) water =10333 (2) water - 240 7 law water of refraction from Suell's nisina = Masino2, =) nair sina = nwater sind sina z -> no dia x sind2 = 1 • 333 x sin (240) 1333 x 0.406 7 0.54218 on a Ć sin'l 0.542) = 32.83 Ang 32.8

case! nia Nair=1 Dz - nwater = 1.333 1 013 32° '. ni sina enz sino 3 sin Oz On hy sinca sin (320) 10333 =0.397538 09 sin! (0.397538) = 23.424 What is the cengle Aug 23.4

Case 2 n = nair = 1 y = 32° air nglass= 1.52 na n2 nz Q glass = new = 1333 n3 o water There are So ist is ni sino- two reflections : = 12 sina 1 x sin 32° = 1052 x sind, sino 2 sin 32° 0.52991-0.3486 152 1.52 O, sin (0.3486 ) 20. you So Angle o in glass is Ang 20.40 and refraction will be - M₂ sina, = no sin az O = 20040 1:52x 0.3486 5 10 333 y sin Qg @3 . sio ( 1152 x 0.3486 so Angle Oz 23.422 Ang 23.4 13486) 1. 333 6