# Linear Motion

A Linear Motion is the movement of a physical object or particle along a straight line.

**AKA:**Rectilinear Motion, Unidimensional Motion**Context:**- It can be described using only one spatial dimension.
- It can simply be described in terms of the magnitudes of displacement, time, velocity and acceleration disregarding the directional components of these vector quantities.
- It ranges between non-uniform linear motion and uniform linear motion.

**Example(s)**- Uniform Linear Motion.
- Non-Uniform Linear Motion.
- A Projectile Motion in the absence of air resistance, rotation and any external forces or components of external forces that can act horizontally.

**Counter-Example(s):****See:**Circular Motion, Non-Uniform Linear Motion, Uniform Linear Motion, Displacement Vector, Velocity, Acceleration, Time.

## References

### 2016

- (Wikipedia, 2016) ⇒ https://www.wikiwand.com/en/Linear_motion Retrieved: 2016-5-22.
**Linear motion**(also called**rectilinear motion**is a motion along a straight line, and can therefore be described mathematically using only one spatial dimension. The linear motion can be of two types: uniform linear motion with constant velocity or zero acceleration; non uniform linear motion with variable velocity or non-zero acceleration. The motion of a particle (a point-like object) along a line can be described by its position [math]x[/math], which varies with [math]t[/math] (time). An example of linear motion is an athlete running 100m along a straight track.Linear motion is the most basic of all motion. According to Newton's first law of motion, objects that do not experience any net force will continue to move in a straight line with a constant velocity until they are subjected to a net force. Under everyday circumstances, external forces such as gravity and friction can cause an object to change the direction of its motion, so that its motion cannot be described as linear.

One may compare linear motion to general motion. In general motion, a particle's position and velocity are described by vectors, which have a magnitude and direction. In linear motion, the directions of all the vectors describing the system are equal and constant which means the objects move along the same axis and do not change direction. The analysis of such systems may therefore be simplified by neglecting the direction components of the vectors involved and dealing only with the magnitude.

- Neglecting the rotation and other motions of the Earth, an example of linear motion is the ball thrown straight up and falling back straight down.

### 1963

- (Feynman et al., 1963) ⇒ Richard P. Feynman, Robert B. Leighton and Matthew Sands (1963, 1977, 2006, 2010, 2013) "The Feynman Lectures on Physics": New Millennium Edition is now available online by the California Institute of Technology, Michael A. Gottlieb, and Rudolf Pfeiffer ⇒ http://www.feynmanlectures.caltech.edu/