The light path is as shown in the figure; Light refracts when it reaches the interface between medium and air after reflection, which is obtained fro
The light path is as shown in the figure; Light refracts when it reaches the interface between medium and air after reflection, which is obtained from geometric relationship and refraction law. If the refracted ray PQ is parallel to the incident ray DC, ∠POA=∠COA=i, sini=, I = 60.
According to the geometric relationship, r = I/2 = 30 and sinr= 1/2, so n=sini/sinr=.
This topic examines the refraction of light, mainly according to the geometric relationship and the formula of refractive index, drawing the light path diagram and solving it. This topic is not difficult.