Study Notes
The rate of change in geometry often refers to how quickly a variable changes over time, such as speed in travel graphs.
- Travel Graph — a graph showing distance travelled over time. Example: A travel graph can show when a person is stationary or moving.
- Distance-Time Graph — a graph that represents the distance travelled over a period of time. Example: A horizontal line indicates no change in distance, meaning the object is stationary.
- Constant Speed — when an object moves at the same speed over time. Example: A straight line on a distance-time graph indicates constant speed.
- Acceleration — when an object's speed increases over time. Example: A curved line getting steeper on a distance-time graph indicates acceleration.
- Deceleration — when an object's speed decreases over time. Example: A curved line becoming less steep on a distance-time graph indicates deceleration.
Exam Tips
Key Definitions to Remember
- Travel Graph: A graph showing distance over time.
- Distance-Time Graph: A graph representing distance travelled over time.
- 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 the object is stationary.
- How can you tell if an object is accelerating on a graph? The line is getting steeper over time.
- What does a straight line on a distance-time graph represent? It represents constant speed.
What Examiners Usually Test
- Understanding of how to interpret travel graphs.
- Ability to identify periods of acceleration and deceleration.
- Calculating speed from a distance-time graph.