Lesson Plan

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Lesson Plan
Grade: Year 12 (A‑Level) Date: 17/01/2026
Subject: Physics
Lesson Topic: recall and use F = mrω2 and F = mv2 / r
Learning Objective/s:
  • Describe the relationship between centripetal force, mass, radius, angular velocity, and linear speed.
  • Derive and select the appropriate formula (F = m r ω² or F = m v² / r) for a given set of data.
  • Apply the formulas to solve quantitative problems involving circular motion, including necessary unit conversions.
  • Identify and correct common misconceptions such as confusing centripetal and centrifugal forces.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint slides with derivations and diagrams
  • Worksheet with practice problems
  • String and small masses for a tabletop demonstration
  • Calculator (or calculator app)
  • Ruler or measuring tape for measuring radii
 Introduction:
Imagine a stone whirled on a string or a car navigating a circular track – both rely on a force pulling toward the centre. Students already know Newton’s second law and basic kinematics, which they will extend to circular motion. By the end of the lesson they will be able to choose the correct centripetal‑force formula and justify their choice.
Lesson Structure:
  1. Do‑now (5'): Quick quiz on forces and vectors from the previous lesson.
  2. Mini‑lecture (10'): Derive F = m r ω² and F = m v² / r, discuss when each is most convenient.
  3. Guided example (10'): Work through the provided tension problem, modelling each step on the board.
  4. Hands‑on activity (15'): Students use string, masses, and a stopwatch to measure r and v, then calculate tension using both formulas.
  5. Independent practice (10'): Worksheet with mixed problems; teacher circulates to offer support.
  6. Check for understanding (5'): Exit ticket – students write which formula they would use for a new scenario and why.
Conclusion:
We recap the link between angular speed, linear speed, and centripetal force, emphasizing the interchangeable forms of the equation. Students hand in their exit tickets, demonstrating their ability to select the appropriate formula. For homework, they complete the additional set of circular‑motion problems in the textbook chapter.