1 Measurements and Uncertainties

Introduction: “This topic is different from other topics in the course book. The content discussed here will be used in most aspects of your studies in physics. You will come across many aspects of this work in the context of other subject matter. Although you may wish to do so, you would not be expected to read this topic in one go, rather you would return to it as and when it is relevant.”

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1.1 Measurements in physics

]]UNDERSTANDING]]

• ]]Fundamental and derived SI units]]
• ]]Scientific notation and metric multipliers]]
• ]]Significant figures]]
• ]]Orders of magnitude]]
• ]]Estimation]]

Quantities and units

Physical quantities = things that are measurable (mass, length, time, electrical current, ect.)

Quantities are related to one another by equations such as ρ = m/V [note: symbols will be written in italics font, and units will by written in Roman (upright) font. “m“ is quantity mass but “m“ is unit meter.]

Fundamental quantities = quantities considered so basic that all other quantities need to be expressed in terms of them. In density formula (ρ = m/V), only mass is fundamental; density and volume are derived quantities.