# FHSST Physics/Rectilinear Motion/Definition

Rectilinear Motion The Free High School Science Texts: A Textbook for High School Students Studying Physics Main Page - << Previous Chapter (Forces) - Next Chapter (Momentum) >> Definition - Speed and Velocity - Graphs - Equations of Motion - Important Equations and Quantities

# What is rectilinear motion?

Rectilinear motion means motion along a straight line. This is a useful topic to study for learning how to describe the movement of cars along a straight road or of trains along straight railway tracks. In this section you have only two directions to worry about: (1) along the direction of motion, and (2) opposite to the direction of motion.

To illustrate this imagine a train heading east.

If it is accelerating away from the station platform (P), the direction of acceleration is the same as the direction of the train's velocity — east. If it is braking the direction of acceleration is opposite to the direction of its motion, i.e. west.