Question: A glass plate whose index of refraction is 1.5 is immersed in a liquid. The surface of the glass is inclined at an angle of 47.0° with the vertical. A horizontal ray in the glass is incident on the interface. When the liquid is a certain alcohol, the incident ray arrives at the interface at the critical angle.
A- What is the index of refraction of the alcohol?
Please use as much detail as possible in your answer. Thanks.