Lesson Plan

• Describe the relationship between the gradient of a speed‑time graph and acceleration.
• Calculate acceleration by determining Δv and Δt from a straight‑line segment on a speed‑time graph.
• Interpret the sign of the gradient to identify positive or negative acceleration.
• Apply the method to solve typical IGCSE‑style questions and avoid common errors.

• Projector and screen
• Whiteboard and markers
• Speed‑time graph worksheets
• Calculators
• Rulers (for measuring gradients)
• Printed worked‑example handout
• Sticky notes for exit tickets

Show a short video of a car accelerating and ask students what the slope of its speed‑time graph represents. Review that acceleration is the rate of change of speed. Explain that today they will learn to read the gradient of a speed‑time graph, calculate the corresponding acceleration, and demonstrate the procedure independently.

1. Do‑now (5') – Quick quiz on definitions of speed, velocity and acceleration.
2. Mini‑lecture (10') – Explain the gradient concept, derive a = Δv/Δt, and display a labelled graph.
3. Guided practice (15') – Work through the provided example together, recording Δv, Δt and calculating a.
4. Pair activity (15') – Students use worksheet graphs to identify a straight‑line segment, compute acceleration and note its sign; teacher circulates for support.
5. Common mistakes discussion (5') – Review typical errors and have students correct a deliberately flawed calculation.
6. Exit ticket (5') – Each student writes one correct acceleration calculation and one common mistake to avoid.

Recap that the gradient of a straight‑line segment on a speed‑time graph gives the object's acceleration, including its direction. Collect the exit tickets to gauge understanding. For homework, assign three additional speed‑time graph problems from the textbook for further practice.