Qualitative Characteristics of Images

Qualitative Characteristics of Images

• Competencies:
  • Predict qualitative characteristics (orientation, type, magnification) of images formed by plane and curved mirrors/lenses.
  • Apply ray diagramming techniques to describe image characteristics and positions.
• Intended Learning Outcomes:
  • Identify properties of images formed by plane, concave, and convex mirrors.
  • Discuss qualitative characteristics of images formed by plane and curved mirrors/lenses.
  • Illustrate image formation from plane, concave, and convex mirrors using ray diagrams.
• Overview (Mirrors):
  • Mirrors are part of daily routines, commonly used in households for personal appearance checks.
  • Plane mirrors produce a single image, multiple images are possible with multiple plane mirrors at angles, akin to a kaleidoscope.
• Activity 1 ("You've Got a Message in a Mirror"):
  • Students are to decipher a message written backward/flipped using a mirror.
  • This activity demonstrates lateral inversion (right-left reversal) of images in mirrors.
• Review:
  • The activity demonstrates lateral inversion in images.
  • Review of properties of images formed by mirrors and lenses from prior modules.
  • The concept of lateral inversion was a module topic.
• Ambulance Example:
  • The word "AMBULANCE" is written backward/flipped on ambulances to appear correctly in the rearview mirror of others. Example of how lateral inversion works in real-life applications.
• Review (Mirrors):
  • Mirrors are reflective surfaces (often glass coated with metals).
  • Light striking a mirror's surface reflects, creating a visual representation or projection.
• Activity 2 ("Light as Rays"):
  • Materials: Plane mirror, laser pointers, protractor.
  • Procedure to measure angles of incidence and reflection.
    • Place mirror on a line.
    • Point laser along incident ray line.
    • Mark reflected ray.
    • Measure angles between normal line (perpendicular to the surface) and incident/reflected rays.
  • Complete a table measuring angles.
• Activity 3 - Fill In The Blanks:
  • Light Speed: 3 x 10⁸ m/s
  • Reflection: Occurs when light bounces off an object.
  • Plane Mirror: A mirror with a flat reflective surface.
  • Angle of Incidence = Angle of Reflection
  • Real image: formed where light rays actually intersect after reflection; can be projected onto a screen.
  • Virtual image: formed where light rays appear to converge; cannot be projected onto a screen.
• Reflection of Light in Mirrors:
  • Law of Reflection:
    • The incident ray, the reflected ray, and the normal line lie in the same plane.
    • The angle of incidence equals the angle of reflection.
• Reflection in Plane Mirrors:
  • Light strikes an object, reflecting in all directions.
  • Reflected light reaching the eyes allows seeing the object.
• Characteristics of Plane Mirror Images:
  • Image is virtual.
  • Same size as the object.
  • Same orientation as the object.
  • Same distance from the mirror as the object.
• Types of Reflection of Light:
  • Specular Reflection: Defined as light reflecting off a smooth surface at a specific angle.
  • Diffused Reflection: Produced by a rough surface, where light reflects in multiple directions.
• Mirror Left-Right Reversal:
  • Viewing yourself in a plane mirror results in an apparent left-right reversal of the image.
  • Raising a hand, the image will appear to raise the opposite (other) hand.
• Mirror Left-Right Reversal (Ambulance example):
  • Information is written laterally/inverted to appear correctly in a rear-view mirror.
• Reflection on Spherical Mirrors:
  • Convex Mirrors: Diverging mirrors (reflecting surface curves outward). Reflection is outwards, cannot be focused.
• Reflecting Surfaces (Real/Virtual Images):
  • Real Image: Light rays actually converge to form the image. Can be projected onto a screen. Real Images are inverted.
  • Virtual Image: Light rays appear to diverge from an apparent intersection point. Cannot be projected onto a screen. Virtual images are upright .
• Ray Diagram Formation by Plane Mirror:
  • A plane mirror creates an image behind the mirror.
  • Images are formed when reflected rays from a point meet (or seem to meet) at a single point.
  • Characteristics of images include location, orientation, size. Images are virtual, upright, and same size.
• Image Formed by Curved Mirrors:
  • Parts: Aperture, Radius of Curvature, Center of Curvature, Pole, Focal Point, Principal Axis and Focal length
• Image Formed by Concave Mirrors:
  • Location of object affects image size and orientation.
• Image Formed by Convex Mirrors:
  • Image is always virtual, reduced, and upright. Location of object doesn't affect image size or orientation.
• Difference Between Convex and Concave Lenses:
  • Convex lens: Converges light rays
  • Concave lens: Diverges light rays
• Seatwork (Multiple questions about characteristics of images and lenses):
  • Questions to identify image properties (real/virtual, upright/inverted, etc.).
  • Questions to identify mirror/lens type (plane, concave, convex).
  • Questions on lens focal length and its use in correcting nearsightedness/farsightedness.