Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: derive P = Fv and use it to solve problems
Learning Objective/s:
  • Describe the relationship between force, velocity, and power and derive the formula P = Fv.
  • Apply the power formula to solve problems involving constant and variable forces.
  • Integrate power over time to obtain work and use energy‑conservation to find unknown quantities.
  • Analyse common misconceptions such as confusing average and instantaneous power.
Materials Needed:
  • Projector or interactive whiteboard for slides
  • Printed worksheet with practice problems
  • Calculator (or graphing calculator)
  • Dynamics experiment kit (blocks, force sensor, motion sensor) for demonstration
  • Whiteboard and markers
 Introduction:
Begin with a real‑world hook: the power output of a car engine while accelerating.
Recall that students already know work, energy, and the definition of power as P = dW/dt.
Success criteria: by the end of the lesson you will derive P = Fv and use it confidently in calculations.
Lesson Structure:
  1. Do‑now (5 min): short question on work‑energy to activate prior knowledge.
  2. Derivation (10 min): teacher walks through the step‑by‑step derivation of P = Fv while students fill notes.
  3. Guided example – constant force (12 min): solve the block‑pull problem together, highlighting the use of energy conservation.
  4. Group activity – variable force (12 min): students work on the spring‑force example, calculate P(x) and identify the maximum power.
  5. Check for understanding (8 min): clicker quiz with conceptual and numerical items.
  6. Summary & exit ticket (8 min): students write one key takeaway and answer a final problem on power.
Conclusion:
Recap the derivation and how P = Fv links force and velocity to instantaneous power.
Collect exit tickets to gauge understanding and assign a worksheet with mixed constant‑ and variable‑force problems for homework.
Remind students to review the vector form P = F·v for upcoming topics on rotating systems.