Position–time graphs
---
👩 Teacher’s Guide
🎯 Objective
Students will be able to:
- Draw and interpret position–time graphs
- Use gradient to calculate speed from a graph
- Describe motion (stationary, constant speed, speeding up) from graph shape
---
📝 Teaching Notes
- Key idea to emphasize: Gradient on a position–time graph represents speed.
- Common misconception: Reading height as speed instead of gradient.
- Suggested teaching approach:
- Draw simple journeys with flat/steep sections.
- Practice gradient triangles with units.
- Link shape to real motion descriptions.
---
💬 Discussion Starter
Ask students:
- How can two journeys have the same average speed but different motion?
- Why do units matter as much as the numbers?
- How can graphs tell a story about motion?
---
🧒 Student Worksheet
Concept and Helping Material
A position–time (distance–time) graph shows how position changes over time. The gradient represents speed: steeper means faster; a flat line means stationary.
---
Vocabulary and Definitions
- — Where an object is relative to a reference point.
- — Slope of a graph; change in y divided by change in x.
- — Not moving; position stays constant.
- — Same speed over time; straight line on distance–time.
- — A larger gradient; indicates faster speed on position–time.
---
Hands-On Experiment or Activities
Activity 1: Walk the Graph
What You Need: masking tape line, stopwatch, graph template.
What You Do: One student walks: stop, slow, fast; another records position every second and graphs it.
Think and Talk: What changed? What stayed the same?
Activity 2: Gradient from Graph
What You Need: printed graphs, ruler.
What You Do: Choose two points, form a gradient triangle, and calculate speed with units.
Think and Talk: What changed? What stayed the same?
---
Practice Questions (QA)
1. What does the gradient of a position–time graph represent?
2. What does a flat (horizontal) line mean?
3. What does a straight sloping line mean?
4. What does a steeper line mean?
5. If the line curves and gets steeper, what does that suggest?
6. How do you calculate gradient?
7. What should the axes be labeled with?
8. Can you find speed at a particular time on a curve?
9. What is displacement on a position–time graph?
10. Why is scale important on graphs?
---
Reflection
- Where do you see this idea in sports, travel, or everyday movement?
- What is one measurement or graph habit that would improve your answers?