### 4.2.2 Dimensional Analysis

This section is not completed yet, but in the meantime here are some practice questions.

Remember:
Units are a clue for whether to multiply or divide. For example, if you have a quantity measured in kilometres per hour (km/h), you need to multiply it by a time in hours to get the number of kilometres. The ‘per hour’ cancels out with the ‘hour’ leaving just kilometres (exactly like if you had $20\div 4$ and multiplied it by $4$, you’d just have $20$ because the fours cancel out): $5\,\mathrm{km/h}\times 3\,\mathrm{h} = 15\,\mathrm{km}$