Can a right-angled prism of clear ice be used for total internal reflection of right through 90degrees, bearing in mind that Ice has a critical angle of 48,8degrees?
To determine whether a right-angled prism of clear ice can be used for total internal reflection, we need to consider the critical angle of ice and the geometry of the prism.
The critical angle is the angle of incidence at which light passing from one medium to another is refracted along the boundary between the two media. For ice, the critical angle is 48.8 degrees.
A right-angled prism has two faces that form a right angle and a third face that connects the other two. In this case, if the prism is made of clear ice, light entering one face can undergo total internal reflection at the other two faces if the incident angle at the first face is greater than the critical angle.
Let's consider a scenario where light enters the prism at an angle of incidence greater than the critical angle of 48.8 degrees. In this case, the light will undergo total internal reflection at the two other faces of the prism because the angle of incidence exceeds the critical angle.
If the incident angle at the first face of the prism is equal to or less than the critical angle, the light will not undergo total internal reflection and will instead refract out of the prism.
So, to answer your question, yes, a right-angled prism of clear ice can be used for total internal reflection if the incident angle at the first face of the prism is greater than the critical angle of ice (48.8 degrees). However, if the incident angle is equal to or less than the critical angle, total internal reflection will not occur.