Measurements, Uncertainty, and Vectors

Vocabulary terms covering measurement methods, SI fundamental and derived units, significant figure rules, temperature conversions, and the classification of physical properties and quantities.

Measurement

The process of comparing a quantity with a standard unit to determine how much of a physical quantity there is.

Water displacement method

A technique used to determine the volume of an irregularly shaped object by measuring the volume of water it displaces in a graduated cylinder.

Micro ($\mu$)

A metric prefix representing one-millionth of a unit, equivalent to $10^{-6}$..

Physical Quantities

Measured properties expressed using a number and a unit, such as $60\,km$.

Fundamental Quantities

Basic quantities that cannot be broken down further and serve as the foundation for all other measurements.

Kelvin ($K$)

The SI unit for temperature, which is an absolute scale where the lowest possible temperature is $0\,K$.

Ampere ($A$)

The fundamental SI unit used to measure electric current.

Candela ($cd$)

The fundamental SI unit used to measure luminous intensity.

Mole ($mol$)

The fundamental SI unit used to measure the amount of a substance.

Derived Quantities

Quantities formed by combining fundamental quantities, such as volume ($m^3$), density ($kg/m^3$), and pressure ($Pa$).

Pascal ($Pa$)

The unit of pressure, equivalent to $\text{kg/ms}^2$.

Significant Figures

Digits in a measurement that represent the tool's capability, including all nonzero digits, zeros between nonzero digits, and final zeros to the right of a decimal point.

Conversion Factor

The ratio of two equivalent quantities used to change units through multiplication or division.

Absolute Zero

The temperature of $0\,K$, at which particles have the least possible motion.

Density

The amount of mass in a given volume, calculated as $\text{Density} = \frac{\text{Mass}}{\text{Volume}}$. Its SI unit is $kg/m^3$.

Intensive Properties

Properties that do not depend on the amount of matter present, such as density and concentration.

Extensive Properties

Properties that depend on the amount of matter present, such as mass and volume.

Scalar Quantities

Physical quantities that possess magnitude only, such as mass, time, temperature, and speed.

Vector Quantities

Physical quantities that possess both magnitude and direction, such as displacement, velocity, force, and acceleration.

Distance-time graph horizontal line

A graphical representation showing that the object is stationary or has zero speed, as distance remains constant over time.

Speed-time graph flat horizontal line

A graphical representation showing that an object is moving with constant speed.