1. OPTICS 1 2 1.Name rays 1&2, and the orange one 2.Where is the angle of INCIDENCE? 3.State the 2 laws of reflection

2. OPTICS air Water Air 1.Name rays 1&2, and the top orange one 2.Where is the angle of INCIDENCE? 3.Describe how the 1st refracted ray has bent. 4.Describe how the 2nd refracted ray has bent. 5.This refractor is called????? 1 2

3. air Water or Glass Air OPTICS 1.Name rays 1&2, and the orange one 2.Where is the angle of INCIDENCE? 3.Describe how ray 1 bent going from water to airfrom air to water 4.Why does it take this line? 5.This refractor is called????? 6.When ray 1 strikes at a slightly larger angle, refraction tries to travel along the surface 7.What is this angle called? 8.Draw this “refraction” ray 9.Draw the actual ray. 10.What is this actually called 1 2

4. OPTICS 1.Name rays 1&2, and the orange one Refracted rays can be identified and recorded using pins The eye above would see that the pins on the REFRACTED ray are in line with the pins on the INCIDENT ray

5. OPTICS – Predicting Refraction Angle See page 172: Snell’s Law for transparent solids: From p 153 some REFRACTIVE INDEXES : crown glass n = 1.52, acrylic (perspex) n = 1.49,water n = 1.33 The CRITICAL ANGLE (c) is the angle in water, glass etc that makes the angle in air = 90°, and makes sin i = 1 From p 154 Some CRITICAL ANGLES crown glass c = 41°, acrylic (perspex) c = 42°, water c= 49°

6. AIR GLASS OPTICS Give the symbol for the NORMAL RAY, the Refractive Indexthe Critical Angle` When angle in AIR = 90°, the angle in Glass is called the CRITICAL ANGLE Sin 90 = 1so

7. AIR GLASS OPTICS Which ray meets the normal at the CRITICAL ANGLE `

8. Air Glass Air OPTICS 1.Name rays 1&2, and the orange ones 2.Where is the angle of INCIDENCE? 3.Describe how ray 1 bent going from air to glass 4.Why does it take this line? 5.This refractor is called????? 1 2 ROYGBIVROYGBIV

9. Principal Axis Focal length OPTICS 1.Two Triangular Prisms are like a convex lens 2.The Principal axis is..... 3.Rays parallel to the Principal Axis meet at______________

10. Principal Axis _ _ _ _ _ _ to _ _ Focal length OPTICS 1.Two Triangular Prisms are like a convex lens 2.A convex lens is thick at the middle and thin at the edge,

11. FOCUS Principal Axis _ _ _ _ _ _ to _ _ Focal length OPTICSRay Writing Rule 1 There are 3 standard rays for finding image positions; any pair will do. 1.A ray from an object travels straight through to image position when it crosses the centre line of lens AND principal axia

12. FOCUS Focal length OPTICS Ray Writing Rule 2 2. FROM an object, A ray PARALLEL to the principal axis bends THROUGH focus to go to image position. The image where the rays meet

13. FOCUS Focal length OPTICS Ray Writing Rule 3 3. from an object, A ray THROUGH focus bends TO BE PARALLEL to the principal axis to go to image position.

14. FOCUS OBJECT IMAGE Focal length OPTICS Virtual Image from Convex Lens Object is between lens and focus. Same rules for lines to lens when beyond 2f. Image is VIRTUAL Dotted arrows show where rays APPEAR to have come from

17. OPTICS Text book, page 174 Problems 2, 3,4,5, 6. Page 157 Problems 1,2,3 Page 159 Problems 1,2,3 Mr Graham 2012