3.1

Learn Like a GEM

Subject: Physics
Lesson: 3.1 General Properties of Waves (Contd..)
Date: 03-04-2026

Table of Contents

• Do Now

• Learning Outcomes

• Core IGCSE Syllabus

• Introduction to Wave Motion

• Mechanical and Electromagnetic Waves

• How Waves are Formed

• Types of Waves

• Properties of Waves

• Displacement-Position Graph

• Displacement-Time Graph

• Wave Equation

• Example Problems

• Exit Ticket

• Thank You

Do Now

• Fig. 7.4 illustrates examples of waves.
    - Transverse Waves:
      - Radio Waves
      - Light Waves
    - Longitudinal Waves:
      - Seismic P-waves
      - Sound Waves
   

• Identify the type of wave based on vibration direction:
    - If the direction of vibration is parallel to the direction of wave movement, it is a longitudinal wave.

Learning Outcomes

• By the end of the lesson, students will be able to:
    - Describe the properties of waves and differentiate between transverse and longitudinal waves.
    - Understand that waves transfer energy without transferring matter.
    - Identify and describe wave properties:
      - Wavelength
      - Frequency
      - Amplitude
      - Crest
      - Trough
    - Apply the wave speed equation:
      $v = f ext{λ}$
    - Recognize the behavior of transverse and longitudinal waves.

Core IGCSE Syllabus

1. Understand that waves transfer energy without transferring matter.

2. Describe wave motion through various examples, including vibrations in ropes and springs, and water waves.

3. Describe features of a wave including:
      - Wavefront
      - Wavelength (λ)
      - Frequency (f)
      - Crest (Peak)
      - Trough
      - Amplitude
      - Wave Speed

4. Recall and use the wave speed equation:
      $v = f ext{λ}$

5. Understand that for transverse waves, vibration direction is perpendicular to wave propagation. Examples include electromagnetic radiation, water waves, and seismic S-waves (secondary).

6. For longitudinal waves, vibration direction is parallel to wave propagation. Examples include sound waves and seismic P-waves (primary).

Introduction to Wave Motion

• Definition of Wave Motion:
    - Wave motion is characterized by periodic motion, which is motion repeated at regular intervals.

• Oscillation or Vibration:
    - An oscillation is one complete cycle of motion.

• Source of Waves:
    - The oscillation or vibration that initiates wave transfer.

• Energy Transfer:
    - Waves transfer energy from one location to another without transferring the medium itself.

• Pendulum Example:
    - A completed oscillation from point A to B and back to A illustrates the concept of oscillation.

Mechanical and Electromagnetic Waves

• Mechanical Waves:
    - Definition: Waves that require a medium for propagation.
    - Examples:
      - Sound Waves
      - Water Waves

• Electromagnetic Waves:
    - Definition: Waves that do not require a material medium and can travel through a vacuum.
    - Examples:
      - Light
      - Ultraviolet (UV)
      - Infrared (IR)
      - Radio Waves

How Waves are Formed

• Waves in a Rope:
    - Particle motion in a rope is perpendicular to wave motion, resulting in transverse waves.

• Waves in a Spring (Slinky):
    - Push-and-pull motion of the hand generates waves in a Slinky. The left-to-right motion of the hand creates longitudinal waves.

Types of Waves

• Longitudinal Waves:
    - Direction of vibration is parallel to the direction of propagation (wave movement).
    - Examples:
      - Sound Waves
      - Slinky Waves
      - Seismic P-waves (Primary)

• Transverse Waves:
    - Direction of vibration is perpendicular to the direction of propagation.
    - Examples:
      - Water Waves
      - Seismic S-waves (Secondary)
      - Slinky Waves (in transverse mode)

Properties of Waves

• Wave Characteristics:
    - Crest: The highest point of a wave.
    - Trough: The lowest point of a wave.
    - Wavelength (λ): Distance between consecutive peaks (crests) or troughs, measured in meters (m).
    - Amplitude (A): Distance from the equilibrium position to the peak of the wave, indicative of the energy carried by the wave.
    - A high amplitude implies more energy.
    - Frequency (f): Number of vibrations or cycles per second, measured in hertz (Hz).
    - Period (T): Time taken for one complete oscillation or one wave to pass a point, measured in seconds (s).

• Wave Speed (v):
    - Defined by the relationship with frequency and wavelength:
      $v = f ext{λ}$

Displacement-Position Graph

• Displacement vs. Position Representation:
    - Illustrates wave properties such as peaks (crests) and troughs.

Displacement-Time Graph

• Displacement vs. Time Representation:
    - Shows periodic behavior and reveals the properties of frequency and period directly.

Wave Equation

• Wave Equation Summary:
    - $ext{Speed (v)} = ext{Frequency (f)} imes ext{Wavelength (λ)}$
    - Units: Speed in m/s, Frequency in Hz, Wavelength in meters (m).

Example Problems

• Problem 1: Calculate the speed of a water wave with frequency 4 Hz and wavelength 3 cm.
    - Calculation: $v = f imes ext{λ} = 4 imes (3/100) = 0.12 ext{ m/s}$

• Problem 2: A wave traveling in the positive x direction with frequency 8.0 Hz. Determine:
    - Amplitude: 15 cm
    - Wavelength: 40 cm
    - Period: TBD
    - Speed: TBD

Exit Ticket

• Complete the sentences using terms from the provided list (energy, matter, sound, light, etc.).

• Figure Analysis:
    - State the number of complete waves shown.
    - Measure amplitude and wavelength on a grid.
    - Label a crest using letter C.

Thank You

• Acknowledgement for participation and learning.