Mirror\n11.5 cm\n14.0 cm\n air 1.00\nglass n_b = 1.52\n47.5°\nθ_1\nθ_2\n air\nglass\nmethanol\n41.3°\n Normal to mirror\nIncident ray\nNormal to rotated mirror\nRay reflected from mirror\nRay reflected from rotated mirror\nMirror\nRotated mirror\nθ\nα\n\n Air\nPlastic\nθ\nθ_crit\n\n α\nθ_crit\nRay\n 53° 37°\n53°\n37°\n \na b #1\n145°\n + #2\n#3 A\nθ_crit\nθ_b\n