Conceptual Physics - Science, Equilibrium, and Newton's First Law

Vocabulary flashcards covering fundamental concepts in physics including the scientific method, forces, mechanical equilibrium, vector math, and Newton's First Law of Motion.

Physics

The science considered to be the most basic of all the physical sciences and the foundation for all other sciences.

Scientific Hypothesis

An educated guess or prediction that must be testable and falsifiable.

Science vs. Technology

Science discovers facts and answers theoretical questions, whereas technology applies scientific facts to solve practical problems.

Force

A push or a pull required to change an object's state of motion.

Net Force

The combination of all forces acting on an object, which changes its motion.

Newton

The scientific and SI unit of force, abbreviated as $\text{N}$, equal to slightly less than a quarter pound.

Tension

A stretching force exerted by a stretched spring, rope, or string.

Vector Quantity

A quantity that requires both magnitude and direction for a complete description, such as force.

Scalar Quantity

A quantity that can be described by magnitude only and has no direction, such as time, area, or volume.

Mechanical Equilibrium

A state wherein no physical changes occur and the net force acting on an object is zero.

Equilibrium Rule

The mathematical rule expressed as $\sum F = 0$, stating that the vector sum of forces acting on an object in equilibrium is zero.

Support Force

The upward force that balances the weight of an object resting on a surface; also commonly called the normal force.

Static Equilibrium

The state of mechanical equilibrium for an object that is at rest.

Dynamic Equilibrium

The state of mechanical equilibrium for an object moving at a constant speed in a straight-line path.

Friction

A contact force between objects that slide or tend to slide against each other, caused by microscopic surface irregularities.

Resultant

The sum of two or more vectors.

Parallelogram Rule

A geometric rule used to find the resultant of two nonparallel vectors by constructing a parallelogram where the vectors serve as adjacent sides.

Natural Motion

According to Aristotle, motion that was thought to be straight up or straight down on Earth, or circular in the heavens, occurring without external forces.

Violent Motion

According to Aristotle, imposed motion resulting from external pushing or pulling forces.

Nicolaus Copernicus

The astronomer who formulated the controversial theory that Earth and other planets move around the sun.

Galileo Galilei

The scientist who demonstrated through experiments with inclined planes that a force is only needed to keep an object moving when friction is present.

Inertia

The property of a body to resist changes to its state of motion.

Newton's First Law of Motion

The law stating that every object continues in a state of rest, or of uniform speed in a straight line, unless acted on by a nonzero net force.

Mass

The quantity of matter in an object and the measure of its inertia, measured in kilograms.

Weight

The gravitational force acting on an object, measured in newtons or pounds.

Volume

A measure of the space occupied by an object, measured in units such as cubic centimeters or liters.