What is the progressive movement?School textbooks clear answers us this question: forward movement of the body (note perfect object - "absolutely solid body" - ATT, devoid of any kind was possible to be deformed!) - is a movement,in which any straight line drawn inside the body (ATT) remains parallel to itself during the whole movement .
answer seems to be exhaustive.The definition given, and on the agenda in favor of translational motion kinematics.At first, this is the simplest case of a uniform rectilinear motion, then - more complicated and interesting for inquiring minds uniformly accelerated (again strictly linear!) Movement, a vivid example of which is the free fall of bodies.Under this section, the pupil becomes acquainted with interesting patterns, stated as follows:
1. the path traveled by the body over successive intervals are related as the squares of the natural numbers : 1: 4: 9: 16 ...
and
2. the path traveled by the body for equal successive intervals correlate the series of odd numbers : 1: 3: 5: 9 ...
In solving problems occurs withinthe necessary methodological and mathematical tools, curious reversible methods of movement , in which all the final data are initial and vice versa (movement as it occurs in the opposite direction, with the countdown).The dynamics of the reverse process of instantaneous velocity vector at all points of a rectilinear trajectory change their direction is reversed, it remains unchanged only the direction of the acceleration vector, genetically associated with the vector resultant of all the forces applied to the body.
Unit "Dynamics of rectilinear motion" as well as kinematics, a priori imply that the movement of the body is a strictly progressive, without turning around any axis and the strain was.Due to these pre-agreed conditions can be neglected dimensions of the body in terms of tasks, considering instead the ideal object - a material point (MT), spatially coincident with the center of gravity (CG) of the body.However, the object MT introduced earlier in the "Kinematics" for when body size is negligible compared to the length of the path.
conservation laws in the case of linear motion are also considered under conditions when we abstract from a possible rotation of the body, believing his move onward (otherwise would be considered reciprocal energy transfer rotational motion into energy of motion forward, and vice versa)
word considered in schoolphysics course forward movement (represented by narrow special case of motion along a straight line!) provides considerable food for thought and theoretical research.You can not say about the experimental section of the school course, studying the progressive movement.Qualitative experimental setup is simply absent in most classrooms.
Even the particular case of rectilinear translational motion is studied primarily in theory.True, not a toy machine Atwood cumbersome and quickly incapacitated inquisitive pupils being permanently installed somewhere on the far wall of the cabinet of physics.Demonstration installations such as sliding along a wire stretched cargo altogether meaningless, because they duplicate the self-sufficient in case of rectilinear motion, which is not identical to the translational motion in the general case.What can I would recommend?Just search for Research in the surrounding reality beyond the physical office with natural wit!
reproduced a textbook example of the Ferris wheel ("Devil's Wheel"), rim and spokes which make rotational movement and observation booths are moving steadily (albeit in a circle!) Convinces us that the forward movement of ATT (and approximately- real body) may be not only straight, but also have any curved path (in this case coincides with the trajectory typology rotational motion MT).
idea of finding cases of the translational motion of the playground (in an experiment, rather than a theoretical argument) "is somewhere near" to the "Ferris wheel".Having come to the playground, we can check whether there are any direct parallel to itself (simulated by any twig or thin rail) when moving the body to all kinds of swings, roundabouts and simulators.It is clear that there will be progressive unless the free fall of an inanimate body, tore off some "climbing frame".
Convinced that a pure translational movement is most often found in nature as a special case - the forward linear motion, with a light heart, we can proceed to the theoretical material of a school textbook.
