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THE VISUAL LEARNING STUDIO
See the idea. Understand the connection.
35 visual explanations across 29 chapters, with topic maps throughout the library.
The chapter index will grow as additional notes are prepared. Chapters shown here are a learning collection, not a claim that the entire exam syllabus is complete.
SEE IT. CONNECT IT. EXPLAIN IT.
Understand the chapter visually
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Study the expanded notes and the credited detailed textbook lessons. The current chapter index covers core topics; it is not a claim of exhaustive coverage of every examination syllabus. Check the official syllabus and primary references.
Speed, Time and Distance — lesson overview
The basic relationship
For uniform speed, distance=speed×time. Average speed is total distance divided by total time across the complete journey.
Convert units before calculating: 1 km h⁻¹ = 5/18 m s⁻¹ and 1 m s⁻¹ = 18/5 km h⁻¹.
A speed is not automatically an average velocity; direction and displacement are separate concerns.
Average speed example
For equal distances at speeds u and v, the average speed is 2uv/(u+v), not generally the arithmetic mean.
Travelling 60 km at 30 km/h takes two hours; returning 60 km at 60 km/h takes one hour. Average speed=120/3=40 km/h.
The arithmetic mean of speeds applies to equal time intervals, not automatically equal distances.
Relative motion
For two objects moving along one line in the same direction, their relative speed magnitude is the difference of speeds; in opposite directions it is the sum.
Crossing problems require the total distance to be covered, including train lengths or platform length where relevant.
Boats-and-stream problems combine a boat’s speed relative to water with the stream’s speed under the assumed straight-line steady-flow model.
