A refractometer is used to identify the source of salt water. It consists of two prisms with refractive index ng = 1.52 and R91 = 1.4-9. A laser beam in the left prism hits the ng an interface at an incidence angle 3 i1 = 25 degrees. The dotted lines are the W to the interfaces between the salt water and the prisms. Take a = 75 degrees. a] Prove mathematically the following relation: 9t1+9 i2 = u. b) If we measure that 912 = 43 degrees, determine the angles Biz, 9t] as well as the refractive index n of this saJt water and please identify its origin using rst the graph and then the table opposite Refractive Index 1 .385 1.375 1.365 1.355 1.3115 1,335 0 50 100150200250 300 350 ' Mass Coneentraon in salt lz'L-ll