Figures 9.31(a) and (b) show refraction of a ray in air incident at 60° with the normal to a glass-air and water-air interface, respectively. Predict the angle of refraction in glass when the angle of incidence in water is 45° with the normal to a water-glass interface [Fig. 9.31(c)].

Explanation

`n_(ga)=1.51, u_(wa)=1.32, n_(gw)=1.144,` which gives `sinr=0.6181` i.e., `r~=38^(@)`