5. A beam of light travels from air into a flat slab of diamond. Its angle of incidence is 0,26 and its angle of transmission is 0 = 10.4. (a) What is the index of refraction of this diamond? (b) How fast does the light travel while in the glass? 6. A laser sits inside a vat of oil (n = 1.52). Its laser beam travels diagonally up through the oil and then out into the external air. If the beam in the air travels effectively along the surface of the oil (0,= 90), what is the incident angle of the beam in the oil relative to the surface normal?