The discussion focuses on determining the angle at which light emerges from an equilateral triangular prism with an index of refraction of 1.5, surrounded by air. Using Snell's Law, participants calculated the angles of incidence and refraction, identifying a discrepancy in the expected output angle. The correct emergence angle relative to the horizontal is 47 degrees, while an incorrect calculation yielded 77 degrees. The importance of visualizing the light path and understanding the relationship between the angles and the prism's geometry is emphasized.
PREREQUISITESStudents studying optics, physics educators, and anyone interested in the practical applications of light behavior in prisms and optical devices.
Let'sthink said:Draw a rough sketch and see whether the refracted ray is meeting the opposite face of the prism or which face of the prism! Check the angle of 49.47 you have got is between refracted ray and which face of prism. Just do not play with numbers visualize what is happening.
That would be with respect to the local normal to the prism. What's the normal's angle with respect to the horizontal? (You were asked for the ray's angle with respect to the horizontal).OhBoy said:Snells law tells me that the refracted ray on the right side should be arcsin(1.5*sin(40.53)), which is about 77 degrees. This answer is off by 30 degrees for some reason. The answer is 47 degrees but I get 77 degrees.
gneill said:That would be with respect to the local normal to the prism. What's the normal's angle with respect to the horizontal? (You were asked for the ray's angle with respect to the horizontal).