Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: recall and use λ = h / p
Learning Objective/s:
  • Recall the de Broglie relation λ = h/p and its derivation from photon equations.
  • Calculate particle momentum (p = mv) and apply λ = h/p to determine wavelength for electrons, neutrons, etc.
  • Explain how wavelength varies with mass and speed and why macroscopic objects do not show observable diffraction.
  • Interpret experimental evidence (electron diffraction, neutron interferometry) that supports wave‑particle duality.
  • Solve quantitative practice problems involving the de Broglie wavelength.
Materials Needed:
  • Projector or interactive whiteboard for slides and derivation.
  • Scientific calculators or computers with spreadsheet software.
  • Handout containing the de Broglie formula, constants, and practice questions.
  • Whiteboard and markers.
  • Video or images of electron diffraction patterns.
  • Worksheets for guided practice.
 Introduction:
Begin with a striking image of electron diffraction to hook students, then ask how particles can behave like waves. Review the concept of momentum (p = mv) and the Planck constant. State that by the end of the lesson students will be able to calculate λ using λ = h/p and explain its physical significance.
Lesson Structure:
  1. Do‑now (5') – Quick quiz on momentum and wave concepts (paper).
  2. Mini‑lecture (10') – Derive the de Broglie relation from photon equations, emphasise h and p.
  3. Guided example (10') – Work through the 150 V electron calculation; students follow on worksheet.
  4. Interactive simulation (8') – Use an online app to vary mass/speed and observe changes in λ.
  5. Group activity (12') – Students solve the three practice questions, then discuss answers.
  6. Concept check (5') – Exit ticket: one‑sentence answer to “Why don’t we see diffraction for a baseball?”
Conclusion:
Summarise that λ = h/p links a particle’s momentum to a wave‑like wavelength and that the magnitude determines observable diffraction. Collect exit tickets and highlight common misconceptions addressed. Assign homework: complete two additional de Broglie problems from the textbook and write a short paragraph on real‑world applications such as electron microscopy.