1.6 Scalars and Vectors

Vocabulary flashcards covering key concepts from the lesson on scalars, vectors, displacement, velocity, motion diagrams, and vector addition.

Scalar quantity

A physical quantity described by a single number with a unit; magnitude only.

Vector quantity

A quantity that has both magnitude and direction; represented by an arrow.

Magnitude

The size or length of a vector.

Displacement

The straight-line change in position from initial to final position; includes direction.

Displacement vector

The vector that represents displacement, drawn from the initial position to the final position.

Velocity

The rate of change of position; a vector whose magnitude is speed and whose direction is the direction of motion.

Speed

The magnitude of velocity; how fast an object is moving.

Motion diagram

A diagram showing an object's positions at successive times, with equal time intervals between dots.

Vector sum

The resultant vector obtained when adding two or more vectors (the net displacement).

Tail-to-head method

A method of adding vectors by placing the tail of one vector at the head of the previous vector.

Right triangle

A triangle with a 90-degree angle used to relate components of displacement.

Pythagorean theorem

In a right triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.

Hypotenuse

The longest side of a right triangle; the magnitude of the resultant in a right-triangle displacement.

Net displacement

The overall displacement obtained by summing the individual displacements; the vector sum.

Origin

The starting point of motion; the zero point in a coordinate system.

Coordinate system

A framework with an origin and axes used to describe positions and displacements.

Angle

A measure of rotation from a reference direction to a vector (e.g., north of east).

Direction

The orientation of a vector in space (e.g., north, east, south, west).

Distance

The total length of the path traveled; not necessarily equal to displacement.

Particle model

Treating a moving object as if all its mass were concentrated at a single point for analysis in motion diagrams.