Introduction to Measurement, Units, and Data Analysis

Vocabulary flashcards covering key measurement concepts, physical units, accuracy, precision, scientific notation, and significant figure rules based on the lecture material.

Scale

A measuring device featuring a central pivot point with two arms, where an object is weighed on one side by placing weights on a pan on the opposite side until it becomes level.

Base Unit of Time

The second, which serves as the fundamental unit of time in scientific measurement.

Absolute Zero

A theoretical value extrapolated from data, defined as the lowest possible temperature where all particle motion stops, equivalent to $0\,\text{K}$ or $-273.15^\circ\text{C}$.

Celsius Scale Basis

A temperature scale defined by the behavior of water, which freezes at exactly $0^\circ\text{C}$ and boils at exactly $100^\circ\text{C}$.

Accuracy

A measure of how close a given measurement is to the true value of the quantity being measured.

Precision

A measure of how close a set of repeated measurements are to each other.

Measured Number

A number obtained through laboratory observation, recorded by taking every digit from a digital display or estimating the final digit between scale markings.

Exact Number

A value obtained directly from counting objects or established by definition, such as $12$ items in a dozen.

Scientific Notation

A method of expressing numbers in the form $a \times 10^b$, where $a$ is a value between $1$ and $10$ with one non-zero digit to the left of the decimal point, and $b$ is an integer exponent.

Significant Figures

All meaningful digits in a measured quantity, including all non-zero digits, zeros located between non-zero digits, and trailing zeros that are not acting as placeholders.

Placeholder Zero

A zero whose sole purpose is to place non-zero digits into their correct place-value column.

Multiplication and Division Significant Figure Rule

The mathematical rule stating that the final calculated result must be rounded to match the smallest number of significant figures present in any of the original numbers being operated on.

Addition and Subtraction Significant Figure Rule

The mathematical rule stating that the final result is determined by alignment of place-value columns, terminating at the highest-value column that first loses significance.