(a(i))[1]
Explain what total internal reflection means.
(a(ii))[1]
Explain what the critical angle means.
(b(i))[2]
Calculate the refractive index for the glass.
(b(ii))[1]
Show that the critical angle at the glass-air boundary is $42\degree$.
(b(iii))[3]
On Fig. 7.1, sketch the ray's path through the prism and out into the air, and do not use calculation.