Question

 a) State Snell’s law in equation form.                                                          

 

b) Light crosses from air to water. The angle of incidence is 75⁰. Draw a schematic diagram of this

event.                                     

 c) Calculate the angle of refraction for the event in part b). Take the refractive index of water to be 4/3.   

Answer 1

a). $\frac{sin(\alpha)}{sin(\beta}=\frac{n_2}{n_1}$

b).

$\alpha=75^0$

$n_1=1$

$n_2=\frac{4}{3}$

then from the law Snellulus write down

$\sin(\beta)=\frac{n_1}{n_2}\sin(\alpha)$

$\sin(\beta)=\frac{1}{4/3}\cdot\sin(75^0)=\frac{3}{4}\cdot0.966=0.724$

Then the refractive angle is equal

$\beta=\arcsin(0.724)=46.42^0$