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What changes when you turn the laser?
Drag the laser along the arc. As i grows, what happens to the ray that leaves the glass?
Sugar solution
n = 1.38 · n = 1 ÷ sin c
c = incidence when the refracted ray reaches 90°
Test angle: within 0.5° of c
°
Ideal flat face. The ray enters and leaves the curved face along a radius.