7. A drop of oil is placed on a glass block. The glass has an index of refraction of 1.55. When light shines from the glass into the droplet, total internal reflection occurs at a critical angle of 59.0(degrees).find the index of refraction of oil.(this method is capable of high accuracy and is used in many refractometers)

Question

7. A drop of oil is placed on a glass block. The glass has an index of refraction of 1.55.  When light shines from the glass  into the droplet, total internal reflection occurs at a critical angle of 59.0(degrees).find the index of refraction of oil.(this method is capable of high accuracy and is used in many refractometers)