acceleration: A change in the speed or direction of some object.
constant: (in mathematics) A number that is known and unchanging, usually based on some mathematical definition. For example, π (pi) is a constant equal to 3.14. . . and defined as the circumference of a circle divided by its diameter.
equation: In mathematics, the statement that two quantities are equal. In geometry, equations are often used to determine the shape of a curve or surface.
expression: (in mathematics) A statement that involves combinations of numbers and/or letters (that signify numbers that may vary) and includes directions (or rules) about what to do with those numbers (such as add or divide them, take their logarithm or make combinations of them equal one another).
force: Some outside influence that can change the motion of a body, hold bodies close to one another, or produce motion or stress in a stationary body.
link: A connection between two people or things.
physics: The scientific study of the nature and properties of matter and energy. Classical physics is an explanation of the nature and properties of matter and energy that relies on descriptions such as Newton’s laws of motion. Quantum physics, a field of study that emerged later, is a more accurate way of explaining the motions and behavior of matter. A scientist who works in such areas is known as a physicist.
pi: (in mathematics) Usually written using the Greek letter π. It is a constant equal to 3.14. . . and defined as the circumference of a circle divided by its diameter.
radius: A straight line from the center to the circumference of a circle or sphere.
square: (In mathematics) A number multiplied by itself, or the verb meaning to multiply a number by itself. The square of 2 is 4; the square of 10 is 100.
variable: (in mathematics) A letter used in a mathematical expression that may take on different values.