Introductory Physics and Measurements Vocabulary

Vocabulary flashcards covering introductory physics concepts, scalar and vector quantities, graph rules, metric prefixes, and experimental measurement techniques.

Physical quantity

Anything that can be measured, such as length, time, speed, or force, classified into scalar and vector types.

Scalar quantity

A physical quantity that can be identified completely by its magnitude (value) only, such as density, mass, distance, speed, and time.

Vector quantity

A physical quantity that can be identified completely by its magnitude and direction, represented by a line segment and an arrow, such as displacement, velocity, acceleration, momentum, force, and weight.

Average (Mean)

The central value obtained by dividing the sum of all values by the total number of values: $\text{average} = \frac{\text{Total/sum of all values}}{\text{no. of values}}$.

Directly Proportional

A relationship between two variables where $x \propto y$, represented by a straight line passing through the origin with a constant ratio $\frac{x}{y}$.

Inversely Proportional

A relationship between two variables where $y \propto \frac{1}{x}$, meaning one variable increases as the other decreases, and their product $x y$ is always constant.

Linear relationship (not proportional)

A relationship represented on a graph by a straight line that does not pass through the origin.

Gradient of a line

The steepness of a line on a graph, calculated using a right-angled triangle spanning at least half the graph with the formula $\text{Gradient} = \frac{y_2 - y_1}{x_2 - x_1}$.

Micrometer

An instrument used to measure short lengths up to $1\,cm$ with an accuracy of $0.001\,cm$.

Ruler

An instrument used to measure lengths up to $30\,cm$ with an accuracy of $0.1\,cm$.

Meter rule

An instrument used to measure lengths up to $1\,m$ with an accuracy of $0.1\,cm$.

Measuring tape

An instrument used to measure distances greater than $1\,m$ with an accuracy of $1\,cm$.

Parallax error

An observational error avoided when taking scale readings by looking perpendicular to the scale.

Meniscus

The curved upper surface of a liquid in a tube, read at the bottom for liquids such as water and at the top for mercury.

Displacement can

An apparatus (also called a Eureka can) filled to capacity to measure the volume of a large irregular solid by measuring the volume of water flooded out.

Mass

The amount of matter contained in an object, or the property of an object that resists change in motion, measured in $kg$ or $g$.

Density

The mass per unit volume of a substance, calculated as $\rho = \frac{m}{V}$ and measured in $kg/m^3$ or $g/cm^3$.

Weight

The attractive gravitational force by which the Earth pulls a body towards its center, given by $w = m g$ and measured in Newtons ($N$).

Gravitational field strength ($g$)

The acceleration of free fall near the surface of Earth, equal to $9.8\,m/s^2$.

Electronic timer

An instrument that starts and stops automatically to measure very short time intervals up to $3\,s$.

Complete oscillation

A single full swing of a pendulum starting from one end, moving all the way to the other end, and returning back.

Periodic time

The time taken for one complete swing of a pendulum, calculated using $\text{Periodic time} = \frac{\text{total time of complete swings}}{\text{no. of complete swings}}$.

Light gate

An electronic device using an invisible beam of light to automatically start or stop a timer when the beam is broken.

Interrupt card

A piece of card fixed to a moving trolley that breaks a light gate beam to allow speed calculation via $\text{Speed} = \frac{\text{length of card}}{\text{Time}}$.

Milli-

A metric prefix denoted by $m$, corresponding to a factor of $\times 10^{-3}$ or $0.001$.

Micro-

A metric prefix denoted by $\mu$, corresponding to a factor of $\times 10^{-6}$ or $0.000\,001$.

Nano-

A metric prefix denoted by $n$, corresponding to a factor of $\times 10^{-9}$ or $0.000\,000\,001$.

Kilo-

A metric prefix denoted by $K$, corresponding to a factor of $\times 10^{3}$ or $1\,000$.

Mega-

A metric prefix denoted by $M$, corresponding to a factor of $\times 10^{6}$ or $1\,000\,000$.

Giga-

A metric prefix denoted by $G$, corresponding to a factor of $\times 10^{9}$ or $1\,000\,000\,000$.