Lesson Plan

• Define stress, strain, and Young’s modulus and state their units.
• Explain the linear stress‑strain relationship and the concept of the proportional limit.
• Calculate stress, strain, and resulting extension for a given force and geometry.
• Identify common misconceptions about stress, strain, and Young’s modulus.
• Apply the concepts to solve typical A‑Level practice problems.

• Projector or interactive whiteboard
• Printed worksheet with definitions, example, and practice questions
• Scientific calculators
• Ruler/measurement tools (or virtual simulation)
• Handout of a typical stress‑strain curve
• Sample metal rod diagram or physical model (optional)

Begin with a quick video of a bridge collapsing to highlight why engineers must understand material behaviour. Ask students what forces act on a structure and how they might predict deformation. State that by the end of the lesson they will be able to define stress, strain, Young’s modulus and use these terms to solve quantitative problems.

1. Do‑Now (5'): Students answer a short question on force and area on the board.
2. Direct Instruction (10'): Present definitions, units, and the formula σ = F/A, ε = ΔL/L₀, E = σ/ε with a diagram of the stress‑strain curve.
3. Demonstration/Simulation (10'): Show a virtual stretch of a rod and discuss the linear region versus yielding.
4. Guided Example (10'): Work through the steel‑rod calculation step‑by‑step, checking each formula.
5. Student Practice (15'): Students complete two worksheet problems individually, then compare answers in pairs.
6. Check for Understanding (5'): Quick quiz (exit ticket) with one conceptual and one numerical item.

Summarise how stress, strain, and Young’s modulus interrelate and why they are essential for predicting material performance. Collect the exit tickets to gauge understanding, and assign homework: three additional stress‑strain problems from the textbook.