rectilíneo

Rectilíneo is an adjective used in geometry and physics to describe something that lies along or follows a straight line. The term comes from the Latin rectus, meaning straight, and linea, line. In geometric contexts, a rectilíneo path is a straight-line trajectory, and the shortest distance between two points is measured along such a path.

In geometry, rectilíneo objects include lines and straight-line segments. A straight line in the plane or space is a rectilínea element that extends indefinitely in two directions or from one point to another, without curvature. Rectilíneo motion, by contrast, refers to movement along a straight line and is a common simplifying assumption in kinematics.

In physics, rectilíneo motion describes one-dimensional movement. The position of an object moving rectilíneamente is often described by a coordinate x(t). For uniform rectilíneo motion, the velocity v is constant and the position follows x(t) = x0 + v t. For rectilíneo motion with constant acceleration a, the relations are x(t) = x0 + v0 t + (1/2) a t^2 and v(t) = v0 + a t. These equations describe how displacement, velocity, and time relate when the path remains straight.

Rectilíneo is contrasted with curvilíneo, which describes paths that curve or bend. The concept underpins many practical problems in engineering, robotics, and motion planning, where straight-line assumptions simplify analysis and design.