Grade 10 Lesson 3: Qualitative Characteristics of Images PDF

Lesson 3: Qualitative Characteristics of Images Competencies: Predict the qualitative characteristics (orientation, type, and magnification) of images formed by plane and curved mirrors and lenses. plane, concave, and convex mirrors. Apply ray diagramming techniques in describing...

Lesson 3: Qualitative Characteristics of Images Competencies: Predict the qualitative characteristics (orientation, type, and magnification) of images formed by plane and curved mirrors and lenses. plane, concave, and convex mirrors. Apply ray diagramming techniques in describing the characteristics and the positions of images formed by lenses. I. Intended Learning Outcomes At the end of the lesson, the Grade 10 students are expected to: A. identify the properties of images formed by plane, concave, and convex mirrors; B. discuss the qualitative characteristics of images formed by plane and curved mirrors and lenses. plane, concave, and convex mirrors C. illustrate the image formation from plane, concave, and convex mirrors using ray diagram.  Overview Mirrors have become part of our daily routine. At home, we normally use plane mirror, a type of mirror that can be found in almost every household. We use this to check on what's needed to be fixed on the way we look.  Overview When these plane mirrors are placed next to each other at an angle, it gives our eyes not only one image, not even two but more than that. This is called multiple images. The mechanism of multiple images is used in the fun and colorful kaleidoscope.  Overview When these plane mirrors are placed next to each other at an angle, it gives our eyes not only one image, not even two but more than that. This is called multiple images. The mechanism of multiple images is used in the fun and colorful kaleidoscope.  Activity 1. You`ve Got a Message in a Mirror! What you need: pen science activity notebook and mirror What you have to do: 1. Read the flipped words below by facing the text box in front of a mirror. 2. Write the message you deciphered on your notebook.  Review Did the activity brighten up your day? In the previous modules, you learned about the nature of images formed by different types of mirrors and lenses. One of the properties of images formed by a mirror that you learned in the preceding module is called lateral inversion, wherein your right becomes your left and your left becomes your right. What you did in the activity is a demonstration of this  Review Maybe along the way to school, you happened to see an ambulance rushing its way to the hospital, have you noticed that the word AMBULANCE is written in reverse? Why do you think is this so? Let's have a little recall of what  Review Technically, a mirror is a reflective surface, made of glass coated with metals, which bounces off light that strikes its surface and form a visual representation or projection of an  Activity 2: “Light as Rays” Materials: Plane mirror, Laser Pointers and Protractor Procedure: 1. Put your mirror carefully on the line labeled “mirror”. 2. Point your laser along the incident ray line. 3. Mark the reflected ray line that represents where the light rays go after hitting the mirror. 4. Measure the angles between the normal line and the incident ray. (A normal line is an imaginary line that is perpendicular to the surface). Record this in the table.  Activity 2: “Light as Rays” Then measure the angle between the angle between the reflected ray and the normal line. Put this result in the table too. 5. Repeat the procedure with all the other incident ray lines.  Activity 2: “Light as Rays” Using the protractor, complete the table by writing in the measurement of the angle of incidence and angle of reflection. Do this in your activity notebook or a separate sheet of paper.  Activity 3 Fill in the sentences by choosing the correct answer that you think best completes the statement. Encircle the letter and write the answer on the blank. 1. Light is a form of energy which travels at a speed ____________________ a. 3 x 108 m/s b. 8 x 106 m/s 2. Reflection occurs when light __________________ off an object. a. Bounces b. Transmitted 3. A mirror with flat reflective surface is called ______________________. a. Concave mirror b. Plane mirror  Activity 3 Fill in the sentences by choosing the correct answer that you think best completes the statement. Encircle the letter and write the answer on the blank. 4. The angle of incidence (i) is equal to the angle of __________________ (r), and the incident ray, the _____________________, and the reflected ray are all in the same plane. a. Normal, incident b. Reflection, normal 5. An image formed by the actual intersection of light rays is called ___________. a. Real b. Virtual 6. An image formed by the apparent intersection of rays called __________ a. Real b. Virtual  Reflection of Light in Mirrors The law of reflection states that: 1. The incident ray, the reflected ray, and the normal line to the reflecting surface all lie in the same plane; and 2. The angle of incidence is equal to the angle of reflection.  Reflection in Plane Mirrors When the light hits an object, every part of that object reflects light in all direction. Some of the reflected light reaches our eyes. Thus, we can see an object. Characteristics of images formed by a plane mirror: 1. Image is virtual; 2. Same size as the object; 3. Same orientation as the object; and 4. Same distance from the mirror as the object.  Types of Reflection of Light a. Specular/ Regular reflection. It is defined as light reflected from a smooth surface at a definite angle. b. Diffused/ Irregular reflection. It is produced by a rough surfaces that tend to reflect light in all directions.  Types of Reflection of Light The phenomenon by which a ray of light changes the direction of propagation when it strikes a boundary between different media through which it cannot pass is described as the reflection of light. If the bundle of light rays is incident upon a smooth surface, then the light rays reflect and remain concentrated in a bundle upon leaving the surface. On the other hand, if the surface is microscopically rough, the light rays will reflect and diffuse in many different directions.  Mirror Left-Right Reversal If you view an image of yourself in a plane mirror (perhaps a bathroom mirror), you will quickly notice that there is an apparent left-right reversal of the image.  Mirror Left-Right Reversal That is, if you raise your left hand, you will notice that the image raises what would seem to be its right hand. If you raise your right hand, you will notice that the image raises what would seem to be its left hand. This is often termed left-right reversal.  Mirror Left-Right Reversal The letters in front of the ambulance are written laterally. This is because when seen in rear view mirror by another vehicle, the image of the word would get inverted, letting the driver read the word properly so that he can provide way to the ambulance.  Reflection on Spherical Mirrors 2. The Convex Mirrors Also known as diverging mirror in which the reflective surface bulges towards the light source. Convex mirrors reflect light outwards; therefore, they are not used to focus light. Reflecting surfaces  Reflecting surfaces REAL IMAGE VIRTUAL IMAGE 1. A real image is formed when light 1. A virtual image is formed when rays actually meet after reflection. light rays do not actually intersect after reflection, but they appear to 2. A real image can be formed on a diverge from the mirror. screen. 2. a virtual image cannot be formed 3. A real image is inverted with on a screen. 3. a virtual image is erect with respect to the object. e.g The image respect to the object. e.g The of a distance object formed by a image of an object formed by a concave mirror. convex mirror  Ray Diagram formation by Plane Mirror A plane mirror makes an image of objects in front of the mirror; the image appears to be behind the plane in which the mirror lies. An image is formed by reflection when two or more reflected rays of a point meet at a single point. The image is formed at the point of intersection of the reflected rays. Image formed by Curved Mirrors  Image formed by Curved Mirrors In locating the image formed in curved mirror graphically, six important points are considered. The following important points are enumerated below. Center of Curvature (C)- the center of the sphere whose surface forms the curved mirror. Focal Point (F)- where the light rays meet. Vertex (V)- the point where the principal axis meets the mirror. Principal Axis- the straight line passing through the center of curvature of the mirror.  Image formed by Curved Mirrors: Concave Mirrors Since the focal point is the midpoint of the line segment adjoining the vertex and the center of curvature, the focal length would be one-half the radius of curvature. Image formed by Curved Mirrors: Convex Mirrors Difference between Convex and Concave lens  SEATWORK! Well done! You are almost done with this unit. Let's summarize what you have learned from the lesson and activities by answering the following on a separate sheet of paper. A. Below are the qualitative characteristics of images. Determine whether it is REAL or VIRTUAL type of images: 1. ____________________ is upright. 2. ____________________ is inverted. 3. ____________________ is behind the mirror. 4. ____________________ is formed by convex mirror.  SEATWORK! 5. ____________________ can be projected onto a screen. 6. ____________________ is inverted with the respect to the object. 7. ____________________ is on the same side of the mirror as object. 8. ___________________rays of light do not actually pass through the image. 9. ___________________can be larger, smaller, or the same size as the object. 10.___________________rays of light actually converge and pass through the image  SEATWORK! B. Identify whether the following is PLANE, CONCAVE or a CONVEX MIRROR 1. ____________________ is a curved mirror 2. ____________________ is a flat, smooth mirror 3. __________________forms only virtual images 4. __________________forms real or virtual images 5.__________________forms images that are only virtual 6. __________________forms images that are always upright  SEATWORK! 7. __________________forms images that are always reduced 8. __________________forms images that are behind the mirror 9. __________________forms images that are upright or inverted 10.__________________forms images that are either real or virtual 11.__________________forms images that are left to right reversal 12.__________________forms images that are the same size as the object only 13.__________________forms images that are either smaller/same size/larger than the object  SEATWORK! 14.__________________forms images that are always the same distance from the mirror as the object 15.__________________forms images that are either behind the mirror or on the same side as the object  SEATWORK! C. Identify whether the following is CONCAVE or a CONVEX LENS 1. In the ____________________, the curve faces inward 2. In the ____________________, the curve faces outward 3. ____________________ is a diverging lens that spreads out the light 4. ____________________ is thicker at the center, as compared to its edges 5. ____________________ is thinner at the center, as compared to its edges  SEATWORK! 6. ____________________ is use for the correction of nearsightedness or myopia 7. ____________________ is use for the correction of farsightedness or hyperopia 8. ____________________ is a converging lens which converges the reflected rays 9. ____________________ is called a negative lens because of its negative focal length nature 10.____________________ is called a positive lens because of its positive focal length nature