Learning objective
Explain motion and forces, reproduce the worked example and justify a decision in the case study.
Before you begin
Read a short instruction; for calculations, add, subtract and multiply.
Understand
Average speed equals total distance divided by total elapsed time. Consistent units matter: metres and seconds give m/s. Average speed does not describe every instant of the journey.
Worked example
A 1,200 m walk takes 20 minutes, or 1,200 seconds. Average speed = 1,200 ÷ 1,200 = 1 m/s, equivalent to 3.6 km/h.
Analysis and common mistakes
Include stops in elapsed time when measuring average speed for the whole journey.
Case study — reasoning
A trip covers 2 km in 30 minutes then 2 km in 60 minutes. Average speed is 4 km ÷ 1.5 h ≈ 2.67 km/h, not the simple average of 4 and 2 km/h.
Knowledge check
Summary
Average speed equals total distance divided by total elapsed time. Consistent units matter: metres and seconds give m/s. Average speed does not describe every instant of the journey.
Sources for further study and verification
AI-assisted draft · Educator review not completed · Unofficial supplementary resource