Reflection of the light in the mirror.pptx

LESSON IN MIRROR GRADE 10 SECOND QUARTER

1. NOTE: Use PRESENTER VIEW (REMOVE THIS NOTE AND THE PHOTO FROM THIS SLIDE) SET THE SAME SETTINGS (Indicated in the RED SQUARE) THE POWERPOINT VERSION REQUIRES TO BE 2019, If it is lower than 2019, SOME TRANSITIONS WILL BE SET to FADE SET THE TV VOLUME TO 25 IF EVERYTHING IS SET. PRESS ANY KEY TO CONTINUE…

2. WARNING: FLASHING LIGHTS AND SOME LOUD NOISES and some funnies

3. Light Our Science book will be irrelevant. But computations are sourced from the books. The presentation will be 2 feet deeper than the books.

4. Light In that game, light is an important mechanic. Also in real life, we use light to see clearly. In daylight we use the sun and its REFLECTION to the surface so LIGHT can bounce around. And in the nighttime, we use electrical fixtures that produce light like BULBS, LAMPS and so on… Oh, and! Vision begins with light passing through the cornea. Now, we are going to learn about LIGHT and about REFLECTION.

5. AGENDA What to understand Introduction Reflection of Light in Lenses Reflection of Light in Mirrors Mirrors

6. Introduction Mirrors To understand the concept of a mirror, one must know what is the phenomenon behind the mirror and what makes it a reflecting material. It is defined as a reflecting surface and can be explained by the law of reflection, which states that when a ray of light is made to fall on the reflecting surface of the mirror all lie in the same plane and the angle of incidence is equal to the angle of reflection. They can be plane or spherical. Spherical Mirrors has two kinds, concave and convex mirror.

7. CONCAVE PLANE CONVEX MIRRORS | REFLECTIONS CONVEX CONCAVE PLANE

8. CONCAVE PLANE CONVEX MIRRORS | REFLECTIONS CONVEX CONCAVE PLANE

9. CONVEX It is a curved mirror where the reflective surface bulges out toward the light source. The bulging-out surface reflects light outwards and is not used to focus light. These mirrors form a virtual image as the focal point, and the center of curvature are imaginary points in the mirror that cannot be projected on a screen as the image is inside the mirror. The image looks smaller than the object from a distance but gets larger as the object gets closer to the mirror. Example 1A

10. CONVEX It is a curved mirror where the reflective surface bulges out toward the light source. The bulging-out surface reflects light outwards and is not used to focus light. These mirrors form a virtual image as the focal point, and the center of curvature are imaginary points in the mirror that cannot be projected on a screen as the image is inside the mirror. The image looks smaller than the object from a distance but gets larger as the object gets closer to the mirror. Example 1B

11. CONCAVE PLANE CONVEX MIRRORS | REFLECTIONS CONVEX CONCAVE PLANE

12. CONCAVE Example 2A A curved mirror where the reflective surface is on the inner side of the curved shape. It has a surface that curves inward, resembling the shape of the inner surface of a hollow sphere. These mirrors are also converging mirrors because they cause light rays to converge or come together after reflection. Concave mirrors reflect upside down because of the way they bend light. The curved surface of the mirror causes light rays from the top of an object to be reflected downward and light rays from the bottom of the object to be reflected upward.

13. CONCAVE Example 2B A curved mirror where the reflective surface is on the inner side of the curved shape. It has a surface that curves inward, resembling the shape of the inner surface of a hollow sphere. These mirrors are also converging mirrors because they cause light rays to converge or come together after reflection. Concave mirrors reflect upside down because of the way they bend light. The curved surface of the mirror causes light rays from the top of an object to be reflected downward and light rays from the bottom of the object to be reflected upward.

14. CONCAVE PLANE CONVEX MIRRORS | REFLECTIONS CONVEX CONCAVE PLANE

15. PLANE Example 3B Plane mirror is with a flat reflective surface. It is the simplest type of mirror and is the most common type of mirror used in everyday life. These reflect light rays in a straight line. This angle of incidence is the angle between the incoming ray of light and the normal to the mirror surface. The normal is an imaginary line that is perpendicular to the mirror surface at the point where the light ray strikes the mirror.

16. PLANE Example 3B Plane mirror is with a flat reflective surface. It is the simplest type of mirror and is the most common type of mirror used in everyday life. These reflect light rays in a straight line. This angle of incidence is the angle between the incoming ray of light and the normal to the mirror surface. The normal is an imaginary line that is perpendicular to the mirror surface at the point where the light ray strikes the mirror.

17. LET’S TALK ABOUT Spherical frameworks STARTING NOW… TURN TO PAGE 100

18. Framework of spherical mirrors Spherical mirrors have several key parts, including the principal axis, principal focus, center of curvature, radius of curvature, vertex, and aperture. These parts are important for understanding how spherical mirrors reflect light and form images. The location of the center of curvature and principal focus depends on the type of spherical mirror. For a concave mirror, the center of curvature and principal focus are located in front of the reflecting side. For a convex mirror, the center of curvature and principal focus are located at the back of the reflecting side. Let’s SUMMARIZE THE KEY PARTS!

19. Framework of spherical mirrors Let’s SUMMARIZE THE KEY PARTS! KEY PART DESCRIPTION Principal Axis An imaginary line that passes through the spherical mirror where principal focus and center of curvature are located. Principal Focus (F) A point at the principal axis where all of the reflected rays meet. The focal length (f) is the distance between the principal focus and the vertex of the mirror. Center of Curvature (C) A point at the principal axis that is located at the very center of the spherical mirror. Radius of Curvature (R) The distance between the center of curvature to the spherical mirror. The focal length (f) is equal to half of the radius of curvature. Vertex The point of intersection between the principal axis and the spherical mirror. Aperture The diameter of the spherical mirror.

20. Framework of spherical mirrors Let’s SUMMARIZE THE KEY PARTS! KEY PART DESCRIPTION Principal Axis An imaginary line that passes through the spherical mirror where principal focus and center of curvature are located. Principal Focus (F) A point at the principal axis where all of the reflected rays meet. The focal length (f) is the distance between the principal focus and the vertex of the mirror. Center of Curvature (C) A point at the principal axis that is located at the very center of the spherical mirror. Radius of Curvature (R) The distance between the center of curvature to the spherical mirror. The focal length (f) is equal to half of the radius of curvature. Vertex The point of intersection between the principal axis and the spherical mirror. Aperture The diameter of the spherical mirror.

21. Framework of spherical mirrors Let’s SUMMARIZE THE KEY PARTS! KEY PART DESCRIPTION Principal Axis An imaginary line that passes through the spherical mirror where principal focus and center of curvature are located. Principal Focus (F) A point at the principal axis where all of the reflected rays meet. The focal length (f) is the distance between the principal focus and the vertex of the mirror. Center of Curvature (C) A point at the principal axis that is located at the very center of the spherical mirror. Radius of Curvature (R) The distance between the center of curvature to the spherical mirror. The focal length (f) is equal to half of the radius of curvature. Vertex The point of intersection between the principal axis and the spherical mirror. Aperture The diameter of the spherical mirror. Location of the center of curvature and principal focus Concave Mirror: in front of the reflecting side Convex mirror: at the back of the reflecting side

22. Now Predicting images formed by spherical mirrors using rays Page 100 - 101

23. We can use a simple graphical method to predict the properties of an image formed by a spherical mirror. This method involves tracing the paths of a few particular rays that diverge from a point on the object and are reflected by the mirror. Predicting images formed by spherical mirrors using rays There are four simple steps to follow

24. Predicting images formed by spherical mirrors using rays There are four simple steps to follow Draw a ray of light parallel to the principal axis. This ray will be reflected through the principal focus. Draw a ray of light passing through the focus. This ray will be reflected parallel to the principal axis. Draw a ray through the center of curvature. This ray will be reflected back along its own path. Draw a ray meeting the mirror at the pole. This raw will be reflected so as to make an equal angle with the principal axis.

25. Now Images formed by spherical mirrors Page 101

26. Concave and convex mirrors Structure Concave and convex mirrors differ in structure. The reflecting side of a concave mirror is at the back of the bulge, while the reflecting side of a convex mirror is in front of the bulge Image Formation Concave and convex mirrors also differ in the type of images they form. Concave mirrors can form both real and virtual images, depending on the distance of the object from the mirror. Convex mirrors always form virtual images. Let’s understand it better! Convex Mirrors Concave Mirrors Convex mirrors always form virtual images that are erect and reduced in size. This is why convex mirrors are used in the side mirrors of cars. Convex mirrors provide a wide field of view, which is helpful for drivers to see objects behind them. The image formed by a concave mirror depends on the distance of the object from the mirror. If the object is placed beyond the focal point of the mirror, a real image will be formed. Real images are inverted and can be projected onto a screen. If the object is placed between the focal point and the mirror, a virtual image will be formed. Virtual images cannot be projected onto a screen

27. Let’s understand it better! A great example is a metal spoon of how concave and convex mirrors differ. The back of the spoon acts as a convex mirror, while the scooping portion of the spoon acts as a concave mirror. Convex Mirrors Concave Mirrors Convex mirrors always form virtual images that are erect and reduced in size. This is why convex mirrors are used in the side mirrors of cars. Convex mirrors provide a wide field of view, which is helpful for drivers to see objects behind them. The image formed by a concave mirror depends on the distance of the object from the mirror. If the object is placed beyond the focal point of the mirror, a real image will be formed. Real images are inverted and can be projected onto a screen. If the object is placed between the focal point and the mirror, a virtual image will be formed. Virtual images cannot be projected onto a screen

28. Now The mirror equation and magnificaton Page 101 - 103

29. Mirror equation The mirror equation is a mathematical expression that can be used to determine the properties of an image formed by a mirror. The equation is as follows:   Where: f is the focal length of the mirror s is the object distance (distance from the object to the mirror) is the image distance (distance from the image to the mirror)  

30. Mirror equation The mirror equation can be used to determine the following properties of an image: Image size: The image size is directly proportional to the object size and inversely proportional to the distance between the object and the mirror. Image Type: The image type can be real or virtual. A real image can be projected onto a screen, while a virtual image cannot. Image Orientation: The image orientation can be upright or inverted. Sign Rules

31. Let’s Try The following sign rules apply to the mirror equation: Object Distance ( ): Positive if the object is on the same side of the mirror as the incoming light, negative if the object is on the other side. Image Distance ( ): Positive if the image is on the same side of the mirror as the outgoing light, negative if the image is on the other side. Focal Length ( ): Positive for concave mirrors, negative for convex mirrors.   Sign Rules

32. Let’s Try Example 1: Object distance: 10cm Focal length: 6cm Sign Rules   What is / are Missing?

33. Let’s Try Example 2: Object distance: 10cm Radius of Curvature: 12cm Sign Rules   What is / are Missing?

34. magnification Spherical mirrors can form either magnified or reduced images. Convex mirrors always form reduced images, while concave mirrors can form either magnified or reduced images depending on the location.   Where: M is the magnification is the height of the image h is the height of the object. s is the object distance (distance from the object to the mirror) is the image distance (distance from the image to the mirror)  

35. magnification Using this formula, it is important to remember that all images located above the principal axis are positive and all heights located below the principal axis are negative  

36. Let’s Try Example 1: Object Height: 10cm Image Height: -5cm Object Distance: 10cm Image Distance: -5cm Sign Rules Verify if the magnified is image reduced or enlarged  

37. Activity: It is a curved mirror where the reflective surface bulges out towards the light source. - Convex Mirror A point of intersection between the principal axis and the spherical mirror. - Vertex It is the most common type of mirror. - Plane Mirror The distance between the center of curvature to the spherical mirror. - Radius of Curvature A curved mirror where the reflective surface is on the inner side of the curved shape. - Concave Mirror Sign Rules

38. Activity: It is a curved mirror where the reflective surface bulges out towards the light source. A point of intersection between the principal axis and the spherical mirror. It is the most common type of mirror. The distance between the center of curvature to the spherical mirror. A curved mirror where the reflective surface is on the inner side of the curved shape. Sign Rules

39. Activity: Bobby places a 4.25-cm tall light bulb a distance of 36.2 cm from a concave mirror. If the mirror has a focal length of 19.2 cm, then what is the image height and image distance. Sign Rules