Daily Plans and Assignments: 1. Monday(01/25): Law of Reflection, Plane and Curved Mirrors. HW: Read and Study pages 457-467, then solve probs. 53, 54, 55, and 58 on page 479. 2. Tuesday(01/26): LAB on Reflection of Light. HW: Process data and write lab report, Due Thursday. 3. Wednesday(01/27): Locating Images in Curved Mirrors, Mathematically. HW: Read and Study pages 467-477, then solve probs. 61, 62, 63, 64, 69, and 71 on page 480. 4. Thursday(01/28): The Law of Refraction (Snell's Law), Speed of Light in Transparent Media, and Total Internal Reflection. HW: Read and Study pages 485-492, then solve probs. 67, 68, 69, 70, and 71 on pages 509. 5. Friday(01/29): LAB on Refraction of Light. HW: Process data and write lab report, Due Monday. 6. Monday(02/01): Thin Lens Refraction. HW: Read and Study pages 493-503, then solve probs. 81, 82, 83, 84, and 85 on page 510. 7. Tuesday(02/02): REVIEW I - Light, Reflection, and Refraction. HW: Complete All Review Handouts. 8. Wednesday(02/03): LAB on Convex Lenses. HW: Process data and write lab report, Due Monday. 9. Thursday(02/04): REVIEW II - Light, Reflection, and Refraction. HW: Complete All Review Handouts. 10. Friday(02/05): TEST on Ch. 17 & 18 - Light, Reflection and Refraction. HW: Go to Website for notes on Ch. 19 - Interference and Diffraction. Very Important: If you have any questions, or were absent and need to complete missing work, see me before school (8:00 - 8:30 AM), Lunch, or after school. Best to send an email to persinr@palmbeach.k12.fl.us. Remember, all Make-up Work must be completed within 3 days of absence.
WEBSITE NOTES: Ch. 17&18 - Light, Reflection and Refraction. 1. Light is electromagnetic radiation that consists of oscillating electric and magnetic fields with different wavelengths; it is also capable of stimulating the retina of the eye. 2. Light, moving through a vacuum, a travels in a straight line at a speed c = 3.0 x 108 m/s, and possesses the properties of both waves and particles. 3. The Law of Reflection Of Light states that the angle of incidence is equal to the angle of reflection, θi = θr. Recall that both are measured relative to the normal. 4. The flat mirrors form virtual images that are the same distance behind the mirror as the object is in front. Flat mirror images are also the same size as the object, but are reversed from left to right. 5. Curved mirrors that we will study are either concave, or convex. They are both "spherical-parabolic." This means that they have some properties of both a sphere and a parabola. 6. In particular, these mirrors have a radius of curvature, r, and a focal point, f. The focal length is half the radius of curvature, f = ½r. 7. The mirror equation ( 1/do+1/di = 1/f ) relates object distance do, image distance di, and focal length f of a spherical-parabolic mirror. 8. The magnification equation ( M = hi/ho = -di/do ) relates image height and distance to object height and distance. All distances measured behind a mirror are negative. In front, they are positive. 9.The convex mirror has only one case of image formation. For an object placed at any distance in front of the mirror, the image is virtual (behind the mirror), smaller, and erect (upright, not inverted). 10. A concave mirror has 6 cases of image formation, all dependent on where the object is located relative to the front of the mirror. 11. Refraction is the bending of light rays at the boundary between two media. Refraction occurs only when the incident ray strikes the boundary at an angle. 12. Snell’s law states that when light goes from a medium with an index n1 to another medium with an index n2, it is bent relative to the normal. The equation is n1·sin i = n2·sin r . 13. Light going from materials with a large n to those with a small n is bent away from the normal. Some typical indices of refraction are: vacuum, n = 1.00; air, n = 1.0003; water, n = 1.33. (See page 486.) 14. As a light ray travels from one medium into another medium it changes speed and the light ray will change its direction unless it travels along the normal. For the speed change, v = c/n. 15. Total internal reflection can occur if light travels from a medium with a larger index of refraction, to one with a smaller index of refraction. If the angle of incidence is greater than the critical angle, the light is total internally reflected (fiber optics). The equation is sinθcrit = n2/n1. 16. Light waves of different wavelengths have slightly different refractive indices. Thus they are refracted at different angles. Light falling on a prism is dispersed into a spectrum of colors. 17. Some materials, calcite for example, exhibit double refraction. This means that one incident ray of light produces two refracted ones. 18. Mirages and the visibility of the sun after it has physically set are natural phenomena that can be attributed to refraction of light in Earth’s atmosphere. 19. A lens is a thin piece of glass that refracts, bends, light. The different types of lenses are, double concave, double convex, plano- concave, plano-convex, and convex-o-concave. 20. The location of an image created by a lens can be found using either a ray diagram or the thin-lens equations, which are the same as the mirror equations, 1/do+1/di = 1/f and M = hi/ho = -di/do . 21. The image produced by a converging lens is real and inverted when the object is outside the focal point and virtual and upright when the object is inside the focal point. Diverging lenses always produce upright, virtual images. 22. We will study double convex (convex), and double concave (concave) lenses in detail because they have the most applications. 23. For the concave lens, there is only one case of image formation. But for the convex, we have 6 cases all based on where the object is located. 24. And still, we need these steps to solve any problem in Physics: (i) read the problem and identify the given variables (ii) determine what you are asked to solve for (iii) find the correct motion formula to use (iv) use algebra to isolate the unknown (v) substitute-in the given information and simplify. Answers to Homework: Page 479: 53. 38o, 54. 53o, 106o, 55. 108o, 58. (diagram & explain) Page 480: 61. 20 cm, 62. .50 cm, 63. 1.8 m, 64. real, inverted, larger 69. 5, 71. -24 cm, 9.0 cm Page 509: 67. 1.33, water, 68. 20.8o , 69. 25.4o , 28.9o , 70. 1.24x108 m/s, 71. 24.4o Page 510: 81. (draw diagram), 34 cm, 82. 39.3 cm, 83. 10.0 cm, 84. 14 cm, 85. (draw diagram), -1.8 cm
|