| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Physics |
| Lesson Topic: understand that deformation is caused by tensile or compressive forces (forces and deformations will be assumed to be in one dimension only) |
Learning Objective/s:
- Describe tensile and compressive forces and how they cause one‑dimensional deformation.
- Explain the relationship between stress, strain and Young’s modulus in the elastic region.
- Calculate stress, strain and Young’s modulus from given force, area and extension data.
- Interpret a stress‑strain diagram to identify elastic limit, yield point, plastic region, ultimate tensile strength and fracture.
- Apply the concepts to solve typical A‑Level exam questions involving tensile or compressive loading.
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Materials Needed:
- Projector and screen
- Whiteboard and markers
- Cylindrical rods of different materials
- Force sensor or spring scale
- Digital calipers or ruler
- Worksheet with data tables
- Handout of a stress‑strain graph
- Scientific calculators
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Introduction:
Begin with a short video of a bridge under load to hook interest. Ask students what they know about forces that pull or push on structures, linking to prior work on pressure. State that by the end of the lesson they will be able to predict how materials deform under tensile and compressive forces and demonstrate this with calculations.
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Lesson Structure:
- Do‑now (5') – Quick quiz on force, pressure and basic definitions.
- Mini‑lecture (10') – Define tensile/compressive forces, stress, strain, Young’s modulus; derive σ = F/A, ε = ΔL/L₀, E = σ/ε.
- Demonstration (10') – Perform a tensile test on a rod using the force sensor; students record force and extension.
- Guided practice (15') – In pairs, calculate stress, strain and Young’s modulus from the recorded data using the worksheet.
- Stress‑strain diagram analysis (10') – Plot the points, identify elastic region, yield point, plastic region, UTS and fracture; discuss real‑world relevance.
- Formative check (5') – Exit ticket: one short problem requiring identification of the elastic limit on a given graph.
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Conclusion:
Summarise how tensile and compressive forces lead to measurable stress and strain and how Young’s modulus links them in the elastic region. Collect the exit tickets and remind students to complete the additional worksheet problems for homework, focusing on interpreting stress‑strain diagrams and calculating extensions.
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