Study Notes
The rate of change in geometry often involves understanding how distance changes over time, as shown in travel graphs. These graphs help identify speed, stationary periods, and return points.
- Travel Graph — a graph showing distance travelled over time. Example: A line moving upwards indicates movement away from the start.
- Stationary Period — a time when the distance does not change. Example: A horizontal line on a distance-time graph.
- Constant Speed — when an object moves at the same speed. Example: A straight line with a constant slope.
- Acceleration — when the speed of an object increases over time. Example: A line that gets steeper as time increases.
- Deceleration — when the speed of an object decreases over time. Example: A line that starts steep and becomes more gradual.
Exam Tips
Key Definitions to Remember
- Travel Graph: A graph showing distance over time.
- Stationary Period: A period where distance does not change.
- Constant Speed: Movement at a consistent speed.
- Acceleration: Increase in speed over time.
- Deceleration: Decrease in speed over time.
Common Confusions
- Confusing acceleration with constant speed.
- Misinterpreting a horizontal line as movement.
Typical Exam Questions
- What does a horizontal line on a distance-time graph indicate? It indicates a stationary period.
- How can you tell if an object is accelerating on a graph? The line becomes steeper over time.
- What does a straight line with a constant slope represent? It represents constant speed.
What Examiners Usually Test
- Understanding of how to read travel graphs.
- Ability to identify periods of acceleration and deceleration.
- Calculating speed from a distance-time graph.