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Unit 1.1: Physical Quantities and Measurements
Overview: In physics, it is always important to think critically about the
measurements one makes and the method used to make these
measurements as small inaccuracies add up to form large errors or
uncertainties. In this Chapter, we will be learning the different physical
quantities, their units, and how to measure them. We will also be learning
about scalars, vectors and how to find the resultant of two vectors.
Measuring length
A physical quantity is a property of a material or system that can be
quantified by measurement. Among these physical quantities are length
and time. The easiest way to measure length is to use a meter rule, or a
ruler. For a regular object such as a cube, the ruler can be used to directly
measure it.
Irregular objects like a twisted metal pipe cannot be measured directly, as
the length measured would not be equivalent to the actual length of the
pipe if it was straightened out.