1. Honorato C. Perez, Sr. Memorial Science High School Copyright 2008 PresentationFx.com | Redistribution Prohibited | Image © 2008 Thomas Brian | This text section may be deleted for presentation.PresentationFx.com IMAGES

2. 1. Emergency vehicles such as ambulances are often labeled on the front hood with reversed lettering (e.g., ECNALUBMA). Explain why this is so. 2. If Suzie stands 3 feet in front of a plane mirror, how far from the person will her image be located? 3. If a toddler crawls towards a mirror at a rate of 0.25 m/s, then at what speed will the toddler and the toddler's image approach each other?

4. Copyright 2008 PresentationFx.com | Redistribution Prohibited | Image © 2008 Thomas Brian | This text section may be deleted for presentation.PresentationFx.com An image is a visual reproduction of an object formed by a mirror or a lens. Incident rays coming from an object strike a mirror or a lens may form an image after being reflected or refracted. Mirrors produce images by reflecting light. Lens produce images by allowing light to go through. (refraction) The study of image formation using rays is central to geometric optics.

5. Image location is the location in space where all the reflected light appears to diverge from.

6. In the case of plane mirrors, the image is said to be a virtual image. Virtual images are images which are formed in locations where light does not actually reach. Light does not actually pass through the location on the other side of the mirror; it only appears to an observer as though the light is coming from this location. Nature

7. Real images are formed by curved mirrors. When rays reflected by a mirror or refracted by a lens intersect, the image formed is real image. Such images are formed on the same side of the mirror as the object and light passes through the actual image location.

8. Classification of Images Virtual In the case of plane mirrors, the image is said to be a virtual image. Virtual images are images which are formed in locations where light does not actually reach. Light does not actually pass through the location on the other side of the mirror; it only appears to an observer as though the light is coming from this location. Real Real images are formed by curved mirrors. When rays reflected by a mirror or refracted by a lens intersect, the image formed is real image. Such images are formed on the same side of the mirror as the object and light passes through the actual image location.

9. Orientation An upright image has the same orientation as the object. Example : Your image in a shaving mirror An inverted image is upside down relative to the object

10. Size Three qualitative descriptions of images according to size enlarged diminished unmagnified

11. What is Left-right reversal?  A shirt displaying the word "NIKE" will read "EKIN" when viewed in the mirror; a shirt displaying the word "ILLINOIS" will read "SIONILLI;" and a shirt displaying the word "BOB" will read "BOB.“  This is a switch of reference frames.

13. Two techniques used to locate an image and determine its nature: by computation by ray diagrams

14. Mirrors Mirror form images by reflection. 2 kinds of mirrors a. plane mirrors b. spherical mirrors

15. Kaleidoscopic effect, with multiple images formed.

16. For flat mirrors the Law of Plane Mirrors states that "the image is always the same distance behind the mirror as the object is in front of the mirror." The image, I, and the object, O, always line up along the same normal. The image is upright, but left-right reversed.

17. Image formed in a plane mirror

18. Spherical Mirrors  A spherical mirror is a mirror which has the shape of a piece cut out of a spherical surface.  There are two types of spherical mirrors: concave, and convex

19. Concave Convex

20.  The normal to the centre of the mirror is called the principal axis.  The point V at which the principal axis touches the surface of the mirror is called the vertex.

21.  The point C, on the principal axis, which is equidistant from all points on the reflecting surface of the mirror is called the centre of curvature.  The distance along the principal axis from point C to point V is called the radius of curvature and is denoted R.

22. The point which lies between the centre of curvature and the vertex, is called the focal point, or focus, of the mirror and is denoted with F. The distance along the principal axis from the focus to the vertex is called the focal length of the mirror, and is denoted f.

23. Convex Mirror A convex mirror, fish eye mirror or diverging mirror, is a curved mirror in which the reflective surface bulges toward the light source. The image is always virtual (rays haven't actually passed though the image), diminished (smalle r), and upright.rays

24.  The passenger-side mirror on a car is typically a convex mirror.  In some countries, these are labelled with the safety warning "Objects in mirror are closer than they appear", to warn the driver of the convex mirror's distorting effects on distance perception.

25. concave mirror, or converging mirror, has a reflecting surface that bulges inward (away from the incident light)., Concave mirrors reflect light inward to one focal point, therefore they are used to focus light. Unlike convex mirrors, concave mirrors show different types of image depending on the distance between the object and the mirror itself.

26.  These mirrors are called "converging" because they tend to collect light that falls on them, refocusing parallel incoming rays toward a focus.

27. Sign Rules Sign rule for the object distance: When an object is on the same side of reflecting or refracting surface as the incoming light, the object distance s is positive ; otherwise, it is negative. Sign rule for image distance: When the image is on the same side of the reflecting or refracting surface as the outgoing light, the image distance s’ is positive; otherwise, it is negative. Sign rule for the radius of curvature of a spherical surface: When the center of curvature C is on the same side as the outgoing light, the radius of curvature is positive; otherwise it is negative.

28.  For a plane mirror the object and image distances are related simply by s = - s’