Uniform rectilinear motion: concept and basic characteristics

Uniform and uneven motion are the most important concepts of kinematics. The basic premise of this section of physics is that, considering the translational motion of a particular body, it should be borne in mind that all its points move in the same direction at exactly the same speed. That is why it is not necessary to give a characterization of the motion of the whole given body, we can confine ourselves to only one of its points.

The main characteristics of any movement include its trajectory, displacement and speed. The trajectory is just a line existing only in the imagination, along which the movement of a given material point in space takes place. The displacement is a vector directed from the initial point to the final point. Finally, speed is a general indicator of the motion of a point that characterizes not only its direction, but also the speed of movement relative to any body taken as a reference point.

Uniform rectilinear motion is in many respects an imaginary concept, which is characterized by two main factors - uniformity and straightforwardness.

Evenness of motion means that it is carried out at a constant speed without any acceleration. The straightness of the movement implies that it occurs along a straight line, that is, its trajectory is an absolutely straight line.

Proceeding from all above, it is possible to draw a conclusion, that uniform rectilinear movement is a special kind of movement as a result of which the body for absolutely equal time intervals realizes the same movement. So, having broken a certain interval into equal intervals (for example, for one second), it will be possible to see that for the above motion the body will pass the same distance for each of these segments.

The speed of uniform rectilinear motion is a vector quantity, which in numerical expression is equal to the ratio of the path traversed by the body for a particular time interval to the numerical value of this interval. This value does not depend on time in any way, moreover, it is worth noting that the speed of uniform rectilinear motion at any point of the trajectory coincides absolutely with the displacement of the body. In this case, the quantitative value of the average velocity for an arbitrarily chosen time interval is equal to the instantaneous velocity.

Uniform rectilinear motion is characterized by a special approach to the path that the body passes over a certain period of time. The passed way with this kind of movement is nothing more than a displacement module. The movement, in turn, is the product of the speed with which the body moved, for the time during which this movement was carried out.

It is quite natural that if the displacement vector coincides with the positive direction of the abscissa axis, then the projection of the calculated velocity will not only be positive, but also coincide with the magnitude of the velocity.

Uniform rectilinear motion can be represented, including, and in the form of an equation in which the relationship between the coordinates of the body and time will be reflected.