Glossary
Comprehensive reference of definitions, symbols, and units used across our educational platform.
Definitions
Acceleration
The rate of change of velocity with respect to time. Measured in m/s². A = Δv/Δt
Algebra
Branch of mathematics using symbols to represent numbers and express mathematical relationships.
Arithmetic Mean
The sum of all values divided by the number of values. Also called the average.
Binary
A base-2 number system using only digits 0 and 1. Foundation of digital computing.
Constant
A fixed value that does not change. In equations, often represented by letters like c, k, or π.
Energy
The capacity to do work. Measured in Joules (J). Can exist as kinetic, potential, thermal, and other forms.
Force
A push or pull that can change an object's motion. Measured in Newtons (N). F = ma
Gravity
The force of attraction between masses. On Earth's surface, g ≈ 9.81 m/s².
Hexadecimal
A base-16 number system using digits 0-9 and letters A-F. Common in computing.
Kinetic Energy
Energy of motion. KE = ½mv². Increases with mass and the square of velocity.
Mass
The amount of matter in an object. Measured in kilograms (kg). Not the same as weight.
Median
The middle value in a sorted dataset. Less affected by outliers than the mean.
Mode
The most frequently occurring value in a dataset. A dataset can have no mode, one mode, or multiple modes.
Potential Energy
Stored energy due to position or configuration. Gravitational PE = mgh.
Power
The rate of doing work or transferring energy. Measured in Watts (W). P = W/t
Quadratic Equation
An equation of the form ax² + bx + c = 0. Has at most two solutions.
Significant Figures
Digits in a number that carry meaningful information about its precision.
Speed
The rate of change of distance with time. Speed = Distance / Time. A scalar quantity.
Standard Deviation
A measure of how spread out values are from the mean. Symbol: σ (population) or s (sample).
Variable
A symbol (usually a letter) representing an unknown or changeable value in mathematics.
Velocity
Speed with direction. A vector quantity. Can be positive, negative, or zero.
Work
Energy transferred by a force over a distance. W = F × d × cos(θ). Measured in Joules.
Symbols
| Symbol | Name | Meaning |
|---|---|---|
| π | Pi | Ratio of circumference to diameter ≈ 3.14159 |
| Σ | Sigma (uppercase) | Summation |
| σ | Sigma (lowercase) | Standard deviation (population) |
| μ | Mu | Population mean; micro- prefix (10⁻⁶) |
| Δ | Delta | Change in a quantity |
| √ | Square root | Principal square root |
| ± | Plus-minus | Both positive and negative values |
| ≈ | Approximately equal | Nearly equal to |
| ∝ | Proportional to | Direct proportionality |
| ∞ | Infinity | Unbounded quantity |
Units Reference
SI Base Units
| Quantity | Unit | Symbol |
|---|---|---|
| Length | meter | m |
| Mass | kilogram | kg |
| Time | second | s |
| Electric Current | ampere | A |
| Temperature | kelvin | K |
| Amount of Substance | mole | mol |
| Luminous Intensity | candela | cd |
Common Derived Units
| Quantity | Unit | Symbol | In Base Units |
|---|---|---|---|
| Force | newton | N | kg⋅m/s² |
| Energy | joule | J | kg⋅m²/s² |
| Power | watt | W | kg⋅m²/s³ |
| Pressure | pascal | Pa | kg/(m⋅s²) |
| Frequency | hertz | Hz | 1/s |