Study Notes
Understanding the relationship between speed, distance, and time is crucial for solving problems involving motion. Calculations often involve converting between these quantities and interpreting graphs.
- Speed — the rate at which an object covers distance. Example: A car traveling at 60 km/h.
- Distance — the total length of the path traveled by an object. Example: A runner completing a 5 km race.
- Time — the duration over which motion occurs. Example: A journey taking 2 hours.
- Average Speed — total distance divided by total time taken. Example: If a car travels 400 meters in 20 seconds, its average speed is 20 m/s.
- Distance-Time Graph — a graph showing distance traveled over time, where the gradient indicates speed. Example: A straight line indicates constant speed.
- Speed-Time Graph — a graph showing speed over time, where the gradient indicates acceleration and the area under the graph represents distance. Example: A horizontal line indicates constant speed.
Exam Tips
Key Definitions to Remember
- Speed = Distance ÷ Time
- Average Speed = Total Distance ÷ Total Time
- Gradient of Distance-Time Graph = Speed
- Gradient of Speed-Time Graph = Acceleration
- Area under Speed-Time Graph = Distance
Common Confusions
- Mixing up units when calculating speed, distance, or time
- Misinterpreting the gradient of graphs
- Confusing speed with velocity
Typical Exam Questions
- How far will Riku walk in three hours at 4.25 km/h? 12.75 km
- Change 20 m/s into km/h. 72 km/h
- Calculate the average speed of a train traveling 600 km in x hours. 600/x km/h
What Examiners Usually Test
- Ability to calculate speed, distance, and time accurately
- Understanding and interpreting kinematic graphs
- Converting between different units of speed and time