Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Physics
Lesson Topic: analyse circular orbits in gravitational fields by relating the gravitational force to the centripetal acceleration it causes
Learning Objective/s:
  • Describe how Newton’s law of gravitation provides the centripetal force for a circular orbit.
  • Derive the expressions for orbital speed and period for a satellite in a circular orbit.
  • Apply the derived formulas to calculate speed, period, and compare different orbital radii.
  • Identify and correct common misconceptions about the dependence of gravitational force on speed and mass.
Materials Needed:
  • Projector or interactive whiteboard
  • Slides with equations and diagrams
  • Handout with key formulas and example problem
  • Calculator or computer with spreadsheet
  • Whiteboard markers
  • Worksheets for quick‑check questions
 Introduction:
Begin with a striking image of a satellite streaking across the night sky, asking students how we know how fast it moves. Recall that they have already used Newton’s second law and basic circular motion in previous lessons. Explain that today they will link gravity to centripetal acceleration to predict orbital speed and period.
Lesson Structure:
  1. Do‑now (5'): quick mental‑review quiz on Newton’s law and centripetal force.
  2. Mini‑lecture (10'): derive v = √(GM/r) by equating forces, with board work.
  3. Guided practice (12'): work through the Earth‑satellite example; students calculate speed and period using calculators.
  4. Conceptual check (8'): discuss common misconceptions using clicker questions.
  5. Extension activity (10'): introduce the vis‑viva equation for elliptical orbits and compare with the circular case.
  6. Quick‑check questions (5'): students answer three short problems individually; teacher collects responses as an exit ticket.
Conclusion:
Summarise that orbital speed depends only on the central mass and radius, while period follows Kepler’s third law. Ask students to write one key formula on an exit ticket and explain its physical meaning. Assign a homework problem to derive the orbital period of a moon around Jupiter using the provided data.