28. Light is incident on an equilateral Lucite prism (n = 1.5) at an angle of 35'. Calculate the angle that the light leaves the prism. (66") 29. From inside an aquarium a ray of light is directed at the glass so the angle of incidence, in water, is 30'. (a] Determine the angle of refraction when the ray emerges from the glass into the air. (b) If the angle of incidence in the water is 52" at what angle will the rays emerge from the glass? (42", no ray emerges) water 30 glass 30. The critical angle from rock salt into air is 40.5'. What is the index of refraction for rock salt? (1.54) 31. The refractive indices of diamond and crown glass are 5/2 and 3/2 respectively. What is the critical angle between diamond and glass? (37") Lesson 5: Refraction (Spherical lenses] 32. An object 8.0 cm high is placed 80 cm in front of a converging lens of focal length 25 cm. Determine the image position and its height. (36 cm, -3.6 cm) 33. A lamp 10 cm high is placed 60 cm in front of a diverging lens of focal length 20 cm. Calculate the image position and the height of the image. (-15 cm, 2.5 cm) 34. A typical single lens reflex (SLR) camera has a converging lens with a focal length of 50.0 mm. What is the position and size of the image of a 25 cm candle located 1.0 m from the lens? (5.3 cm, -1.3 cm] 35. A converging lens with a focal length of 20 cm is used to create an image of the sun on a paper screen. How far from the lens must the paper be placed to produce a clear image? (20 cm) 36. A convex lens has a focal length of + 20 cm and a magnification of 4. How far apart are the object and the image? (45 cm) 37. A projector is required to make a real image, 0.50 m tall, of a 5.0 cm object placed on a slide. Within the projector, the object is to be placed 10.0 cm from the lens. What must be the focal length of the lens? (9.1 cm)