Rectilinear motion is found within linear or translational kinematics. This is the description of the motion in space of a point along a line. This line can also be known as a trajectory of a path and if this path is straight, it is said to be rectilinear. In comparison, a curved path is said to be curvilinear.
Kinematics describes the motions of bodies (objects) and systems (groups of objects) without considering the forces that cause these motions. It is a branch of classical mechanics and shouldn’t be confused with analytical dynamics, the study of the relationship between the motion of objects and its causes. Analytical dynamics is sometimes subdivided into kinetics, the study of the relations between external forces and motion, and statics, the study of the relations in a system of equilibrium. Kinematics differs from analytical dynamics due to the fact that it is used in modern-day physics to describe time evolution of a system. While it is not a term that is used as commonly today as it has been in the past, kinematics still has a role in physics, biomechanics and animal locomotion.
Kinematics in its simplest form of application considers particle motion, translational or rotational. At the next level of complexity, kinematics sees the introduction of rigid bodies. These are collections of particles that have time invariant distances between themselves. These rigid bodies may undergo translation and rotation or both. An even more complex application of kinematics is of a system of rigid bodies. Kinematics is used to find a mechanism’s range of movement or to design a mechanism that moves in a desired range. For example, both the movement of a crane and the movement of the oscillations of a piston in an engine are simple kinematic systems. They differ as the crane is a type of open kinematic chain and the piston is part of a four-bar linkage.
Kinematics describes the motions of bodies (objects) and systems (groups of objects) without considering the forces that cause these motions. It is a branch of classical mechanics and shouldn’t be confused with analytical dynamics, the study of the relationship between the motion of objects and its causes. Analytical dynamics is sometimes subdivided into kinetics, the study of the relations between external forces and motion, and statics, the study of the relations in a system of equilibrium. Kinematics differs from analytical dynamics due to the fact that it is used in modern-day physics to describe time evolution of a system. While it is not a term that is used as commonly today as it has been in the past, kinematics still has a role in physics, biomechanics and animal locomotion.
Kinematics in its simplest form of application considers particle motion, translational or rotational. At the next level of complexity, kinematics sees the introduction of rigid bodies. These are collections of particles that have time invariant distances between themselves. These rigid bodies may undergo translation and rotation or both. An even more complex application of kinematics is of a system of rigid bodies. Kinematics is used to find a mechanism’s range of movement or to design a mechanism that moves in a desired range. For example, both the movement of a crane and the movement of the oscillations of a piston in an engine are simple kinematic systems. They differ as the crane is a type of open kinematic chain and the piston is part of a four-bar linkage.
