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

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

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

4. OPTICS 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 • Name rays 1&2, and the orange one

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

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

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

9. OPTICS • Two Triangular Prisms are like a convex lens • The Principal axis is. . . . . • Rays parallel to the Principal Axis meet at______________

10. OPTICS • Two Triangular Prisms are like a convex lens • A convex lens is thick at the middle and thin at the edge,

11. OPTICS Ray Writing Rule 1 • There are 3 standard rays for finding image positions; any pair will do. • A ray from an object travels straight through to image positionwhen it crosses the centre line of lens AND principal axia

12. 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. 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. OPTICS Virtual Image from Convex Lens • Object is between lens and focus. Same rules for lines to lens when beyond 2f. Image is VIRTUALDotted 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