Curved Mirror Images and Their Characteristics

Introduction

  • Overview of the lesson covering curved mirrors, including concave and convex types.

Instructions for the Beginning of Class

  • All electronic devices, including computers, must be placed out of sight (desk or bag).

  • Earplugs should be removed before the class starts.

  • Students need to have a pencil, eraser, and ruler ready.

  • A handout should be picked up at the start of the class.

  • Students are required to answer questions 1-4 on the handout provided.

  • Homework includes completing all pages, which may be done during class or assigned as homework.

Today's Topic: Curved Mirror Images

  • Learning Objectives:

    • E3: Demonstrate an understanding of various characteristics and properties of light, particularly reflection in mirrors.

    • E2.2: Use an inquiry process to investigate the laws of reflection using curved mirrors.

    • E3.3: Describe the characteristics and positions of images formed by curved mirrors based on observation, using ray diagrams (e.g., location, orientation, size, type).

Curved Mirrors

  • Diagnostic Examples:

    • Observations from a mirror in Chicago where people appear much smaller.

    • Reflection of an image (e.g., hand) appearing larger than the actual object.

Classification of Mirrors

  • Types of Mirrors:

    • (a) Convex Mirror: A mirror that bulges outward.

    • (b) Concave Mirror: A mirror that curves inward.

    • (c) Plane Mirror: A flat mirror that does not alter the image's shape or size.

Review: Comparing Mirror Types

Plane Mirrors

  1. Image Characteristics: Upright Orientation

    • Determine which image is upright: virtual or real.

  2. Size and Orientation Changes as Distance Changes

    • When the plane mirror is moved closer:

      • Size of the image: (Circle the answer) increases, decreases, stays the same.

      • Orientation of the image: (Circle the answer) inverted, stays the same.

  3. Distance Increase Effects

    • When moving the plane mirror further away:

      • Size of the image: (Circle the answer) increases, decreases, stays the same.

      • Orientation of the image: (Circle the answer) inverted, stays the same.

Review Findings on Plane Mirrors

  • When an object is positioned in front of a plane mirror:

    • All light rays from the object will strike the mirror and reflect according to the law of reflection.

    • The rays reaching your eye appear to originate from a point behind the mirror.

Image Properties

  • Location: Behind the mirror, at the same distance as the object.

  • Orientation: Upright and laterally inverted.

  • Size: Same size as the object.

  • Type of Image: Virtual.

Identifying Plane Mirrors Examples

  • Common instances include:

    • Dressing mirrors

    • Kaleidoscopes

    • Periscopes (used in submarines)

Concave Mirrors

  • Usage: To create larger images or to focus light onto a single point (e.g., used in microscopes).

Convex Mirrors

  • Application: To provide a larger field of view;

    • Examples include:

    • Security mirrors

    • Side mirrors of vehicles

    • Garage mirrors or road mirrors.

Identifying Different Mirrors

  • Examples of different mirrors in varied contexts:

    • Concave Mirrors: Microscope mirror, bathroom mirror, rearview mirror, side view mirror, dentist tools, satellite dishes, spotlight, shaving mirror.

    • Convex Mirrors: Security mirrors, side view mirrors.

Ray Diagram of a Concave Mirror

  • Key Properties of Concave Mirrors:

    • Principal Axis (PA): The straight line passing through the center of the mirror.

    • Vertex (V): The point where the principal axis intersects the mirror.

    • Focal Point (F): The point where all reflected light rays converge.

    • Focal Length (f): The distance from the focal point to the mirror.

    • Centre of Curvature (C): The center of the sphere from which the mirror is sectioned; it is twice the focal length (i.e., $C = 2f$).

Remembering the Properties of Curved Mirrors: LOST

  • Characteristics should be remembered as follows:

    • Location: Image can appear in front of or behind the mirror.

    • Orientation: The image can be upright or inverted.

    • Size: Images can be smaller, larger, or the same size as the object.

    • Type: Distinguish between real and virtual images.

Activities for Engagement

  • Activity One: Examination and interaction with various types of mirrors.

  • Activity Two: Conduct a virtual mirror lab as part of geometric optics studies.