Problem P. 4221. (January 2010)
P. 4221. The base of a glass prism is an isosceles triangle. The angle between the equal sides is 40^{o} and the refractive index of the glass of the prism is 1.5. What should the angle of incidence of the light beam incident on one of the congruent faces of the prism be in order that the refracted ray is to be parallel to the base of the isosceles triangle. What is the answer if the prism is placed into water of refractive index of 1.33, or into bensole of refractive index 1.6?
(4 pont)
Deadline expired on 10 February 2010.
Sorry, the solution is available only in Hungarian. Google translation
Megoldás. A beesési szög a három esetben rendre \(\displaystyle 30{,}9^{\circ}\); \(\displaystyle 22{,}7^{\circ}\) és \(\displaystyle 18{,}7^{\circ}\).
Statistics:
95 students sent a solution.  
4 points:  70 students. 
3 points:  4 students. 
2 points:  10 students. 
1 point:  9 students. 
0 point:  1 student. 
Unfair, not evaluated:  1 solution. 
