Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: recall and use Newton’s law of gravitation F = Gm1m2 / r2 for the force between two point masses
Learning Objective/s:
  • Describe the variables in Newton’s law of gravitation and their units.
  • Explain the inverse‑square relationship between force and separation distance.
  • Apply the formula F = G m₁ m₂ / r² to calculate gravitational forces in numerical problems.
  • Analyse common misconceptions about gravitational force and correct them.
Materials Needed:
  • Projector or interactive whiteboard
  • Slide deck with formula, diagram and derivation
  • Worksheet with practice questions
  • Scientific calculators
  • Rulers/compass for drawing force diagrams (optional)
  • Answer key for teacher
 Introduction:
Begin with a quick demonstration: drop two objects of different masses and ask why they fall at the same rate. Recall prior learning of forces and vectors, linking to the idea of an attractive force acting at a distance. State that by the end of the lesson students will be able to calculate gravitational forces between any two point masses.
Lesson Structure:
  1. Do‑now (5'): Students solve a short mental‑math question on force units; teacher checks answers.
  2. Mini‑lecture (10'): Present Newton’s law, variables, and inverse‑square concept with slides and diagram.
  3. Guided derivation (8'): Walk through the conceptual derivation steps, prompting student input.
  4. Worked example (7'): Solve the Earth‑satellite problem together, highlighting substitution and calculation.
  5. Independent practice (15'): Students complete three practice questions while the teacher circulates; finish with a quick exit‑ticket (one‑sentence answer).
Conclusion:
Summarise that gravitational force depends on both masses and the square of their separation, with G as the proportionality constant. Invite a few students to share their exit‑ticket answers to confirm understanding. Assign homework: a set of additional problems on gravitational force, including one conceptual explanation.