Physics 109 1nd Edition Lecture 4 Outline of Last Lecture I. Refraction Reviewa. Snell’s Lawb. Critical AngleII. The prism III. Converging Lensa. Lens formula b. 3 easy raysc. MagnificationOutline of Current Lecture I. Diverging lens a. 3 easy raysb. Lens Formula II. Dispersion Current LectureI. Diverging lens are thinner in the middle, so they deflect light rays away from the axisa. The image of a diverging lens is always:i. Virtual ii. Right-side-upiii. In front of lens iv. Smaller than objectb. 3 easy rays:i. The first ray goes straight through the center of the lensii. The second ray is parallel to the optical axis. This ray is deflected out of the lens and appears as if it came from the focal point on the same side as the objectiii. The third ray is the ray from the top of the object heading in the direction of the focal point on the opposite side of the lens with respect to the object. This ray will come out parallel to the axis, seeming to come from the point already identified by the first two raysThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.This image shows the 3 easy rays for a diverging lensThe image is virtual and upright c. Lens Formula i. The lens formula tells you how object distance, o, and image distance, i, are related to the focal length, f, of a lens1. O is the length from the object to the lens2. i is the length from the lens to the image3. f is the length from the lens to the focal pointa. The focal length of a diverting lens is stated as a negative because the image is in front of the lensii. The equation is: 1/i=1/f-1/01. Example: Focal length= -10 cm, object is 10cm from lens. Where is the image?1/i=-1/10-1/10=-2/10=-1/5i=-5cm, so the image is 5 cm from the lens, on the same side of the lensII. Dispersiona. The index of refraction is different for different colors!i. Red is a primary color because it is very difficult to kink, blue kinks