Lesson Plan

Lesson Plan
Grade: Date: 01/12/2025
Subject: Physics
Lesson Topic: derive, using the definitions of speed, frequency and wavelength, the wave equation v = f λ
Learning Objective/s:
  • Describe the definitions of wave speed, frequency and wavelength.
  • Derive the wave equation v = f λ from those definitions.
  • Apply the equation to calculate any one of the three quantities given the other two.
  • Explain why the relationship holds for both transverse and longitudinal waves.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint/Google Slides with wave diagrams
  • Worksheet with derivation steps and practice problems
  • Scientific calculators
  • Rulers or string for hands‑on wavelength demonstration
Introduction:
Begin with a short video of ocean waves and a sound clip of a tuning fork to hook interest. Ask students what they already know about speed, frequency and wavelength from previous lessons. State that by the end of the lesson they will be able to derive and use the wave equation to solve real‑world problems.
Lesson Structure:
  1. Do‑Now (5'): Quick quiz on definitions of v, f, λ displayed on the board.
  2. Mini‑lecture (10'): Present the derivation step‑by‑step, linking each algebraic move to the physical definition.
  3. Guided practice (12'): Work through the worked example together, prompting students to fill in each algebraic step.
  4. Conceptual check (8'): Discuss the two conceptual questions in small groups, then share answers.
  5. Hands‑on activity (10'): Use rulers/strings to model a sinusoidal wave and measure λ and T, then calculate v.
  6. Formative check (5'): Exit ticket – write the wave equation and one real‑world example where it applies.
Conclusion:
Summarise how the wave equation unites the three core wave properties and why it is universally valid. Collect exit tickets to gauge understanding and assign a short homework: three problems requiring calculation of v, f, or λ. Remind students to review the diagram of a progressive wave for the next lesson.