Introduction to Measurement and Significant Figures

Flashcards covering the fundamentals of measurement, SI units, mass vs. weight comparison, significant figure rules, and scientific notation based on lecture notes.

Measurement

A process of determining or estimating the magnitude of a quantity, involving comparison with a standard.

Direct Method

The process of taking measurement with the use of a measuring device, producing fundamental or basic physical quantities.

Fundamental Quantity: Length / Distance

Measured using the SI unit meter ($m$).

Fundamental Quantity: Mass

Measured using the SI unit kilogram ($kg$).

Fundamental Quantity: Time

Measured using the SI unit second ($s$).

Fundamental Quantity: Electric Current

Measured using the SI unit ampere ($A$).

Fundamental Quantity: Thermodynamic Temperature

Measured using the SI unit kelvin ($K$).

Fundamental Quantity: Amount of Substance

Measured using the SI unit mole ($mol$).

Fundamental Quantity: Luminous Intensity

Measured using the SI unit candela ($cd$).

Thermometer

A basic measuring tool used to measure the average kinetic energy of a substance (temperature).

Ammeter

A tool used to measure electric current.

Digital Balance

A device used to measure the amount of a substance.

Weighing Scale

A tool used to measure the mass of a matter.

Lord Kelvin

A Scottish mathematician and physicist who developed the Kelvin temperature scale.

André-Marie Ampère

A physicist who studied the behavior of charges, after whom the unit for electric current was named.

Indirect Method

The process of taking measurement with the use of a formula or a combination of direct methods, leading to derived physical quantities.

Factor Label Method (Dimensional Analysis Method)

Methods used to perform the conversion of measurements.

King Henry 1

The English ruler during whose reign a foot was defined as $12$ inches.

Hertz ($Hz$)

The unit in which frequency is measured.

Mass

A scalar quantity representing the quantity of matter in a body ($m = \frac{F}{a}$) which is constant everywhere in the universe; measured in kilograms ($kg$).

Weight

A vector quantity representing the gravitational force acted upon the mass of a body ($W = mg$) which changes depending on location; measured in newtons ($N$).

Ampere ($A$)

Equal to the flow of approximately $6 \times 10^{18}$ (6 quintillion) electrons past a single point per second.

Mole ($mol$)

A shorthand way to talk about huge amounts of tiny things, where one mole equals about $6 \times 10^{23}$ (600 sextillion) of an item.

Candela ($cd$)

The unit for luminous intensity, which is about equal to the light given off by a single candle.

Meter ($m$)

The distance light travels in just $1/299,792,458$ of a second through empty space (vacuum).

Absolute Zero

The coldest temperature, defined as $0\,K$, where atoms are cooled to their limit.

Uncertainty

The aspect of measurement that indicates how much error is present and how much a number may differ from the actual true value.

Significant Figures

The digits of value which carry meaning towards the resolution of a measurement.

Significant Figures Rule for Rounding (Multiplication & Division)

Round the final answer to match the least number of significant figures found in the original numbers.

Significant Figures Rule for Rounding (Addition & Subtraction)

Round the final answer to match the least number of decimal places present in the starting numbers.

Scientific Notation

A way for scientists to write and work with very large and very small numbers more easily using powers of $10$.