Ratio, proportion & rates of change · Compound units & rates
Chapter 1 · 4
The idea
Converting compound units and rates of flow
Why converting a compound unit means converting both of its parts, where the ÷3.6 between km/h and m/s comes from, why g/cm³ to kg/m³ is ×1000, and how rates of flow work.
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Ratio, proportion & rates of change · Compound units & rates
Converting compound units and rates of flow
Why converting a compound unit means converting both of its parts, where the ÷3.6 between km/h and m/s comes from, why g/cm³ to kg/m³ is ×1000, and how rates of flow work.
Why it works
Convert BOTH parts
A compound unit like km/h is built from two simple units — so converting it means converting both parts, top and bottom. Convert only one and the answer is silently wrong: the number looks plausible, the units claim something else entirely. Every conversion in this lesson is the same three-step recipe — write the rate as a fraction of units, convert top and bottom separately, recombine.km/h to m/s, from first principles
Take 54 km/h. Convert the top: km m. Convert the bottom: 1 hour s. SoKeep reading — free
The rest of the explanation, plus 2 worked examples you step through move by move.
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