| Lesson Plan |
| Grade: |
Date: 01/12/2025 |
| Subject: Physics |
| Lesson Topic: Electric fields |
Learning Objective/s:
- Describe the effect of damping on simple harmonic motion and identify under‑, critical‑, and over‑damped regimes.
- Explain how a periodic driving force produces forced oscillations and defines resonance.
- Apply the mechanical‑electrical analogy to relate an RLC circuit to a damped driven oscillator.
- Calculate the steady‑state amplitude and phase lag for given system parameters.
- Evaluate the quality factor Q and predict the sharpness of resonance.
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Materials Needed:
- Projector or interactive whiteboard for equations and diagrams
- Printed worksheet with example problem and data tables
- Graphing calculator or computer with spreadsheet software
- Spring‑mass‑damper demonstration kit (or video)
- RLC circuit simulation app (e.g., PhET)
- Whiteboard markers and eraser
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Introduction:
Begin with a short video of a swinging pendulum that gradually slows, asking students what causes the decay. Recall previous work on simple harmonic motion and natural frequency. Explain that today they will explore how damping and external driving forces modify SHM and how the same mathematics describes electric fields in RLC circuits. Success will be measured by correctly predicting resonance conditions and solving a quantitative problem.
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Lesson Structure:
- Do‑now (5') – Quick quiz on undamped SHM and natural frequency.
- Mini‑lecture (15') – Introduce damping, present the equation, discuss under‑, critical‑, and over‑damped regimes with sketches.
- Interactive simulation (10') – Use a PhET RLC circuit simulation; students record amplitude versus driving frequency.
- Guided derivation (15') – Derive steady‑state amplitude and phase lag; highlight resonance condition and Q factor.
- Worked example (10') – Pair work solving the provided mass‑spring problem step‑by‑step.
- Concept check (5') – Polling question on resonance frequency shift for heavy damping.
- Summary & exit ticket (5') – Students write one correct statement about resonance and one common misconception they have corrected.
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Conclusion:
Summarise how damping alters the amplitude envelope and shifts the resonance frequency, linking back to the electric field analogy in an RLC circuit. Ask learners to submit an exit ticket stating the resonance condition and one factor that influences Q. Assign homework to model a series RLC circuit in a spreadsheet and plot its amplitude response. Reinforce that mastering these ideas prepares them for later topics on wave propagation and signal processing.
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