Uniform motion and its features

Among the variety of movements studied by suchthe division of physics, like kinematics, is such that the body for any arbitrarily taken equal intervals of time passes the same length along the length of the path. This is a uniform movement. An example is the movement of a skater in the middle of a distance or a train on an even stretch.

Theoretically, the body can move on anytrajectory, including curvilinear. In this case, there is the concept of a path - this is the distance traveled by the body along its trajectory. The path is a scalar quantity, and it should not be confused with the displacement. The last term we denote the segment between the starting point of the path and the final one, which, in the case of curvilinear motion, obviously does not coincide with the trajectory. Moving is a vector value having a numerical value equal to the length of the vector.

There is a natural question - in which casesis it about uniform movement? Will the movement, for example, carousel in a circle with the same speed, be considered uniform? No, since with this motion the velocity vector changes its direction every second.

Another example is that the car rides in a straight line withthe same speed. This movement will be considered uniform until the car does not turn off and on the speedometer its the same number. It is obvious that uniform motion always occurs along a straight line, the velocity vector does not change in this case. The path and the movement in this case will be the same.

Uniform movement is a movement in a straight linetrajectory with a constant speed, at which the lengths of the traversed paths for any equal time intervals are the same. A particular case of uniform motion can be considered a state of rest, when the velocity and the traversed path are zero.

Speed ​​is a qualitative characteristicuniform motion. Obviously, different objects pass through the same path at different times (pedestrian and car). The ratio of the path traversed by a uniformly moving body to the length of time for which this path is traversed is called the speed of motion.

Thus, the formula describing the uniform motion looks like this:

V = S / t; where V is the speed of motion (is a vector quantity);

S - path or movement;

t is time.

Knowing the speed of motion, which is unchanged, we can calculate the path traveled by the body for any arbitrary time interval.

Sometimes mistakenly mix a uniform anduniformly accelerated motion. These are completely different concepts. Equal-accelerated motion is one of the variants of non-uniform motion (ie, one in which the velocity is not a constant value), which has an important distinctive feature - the speed with this type of motion changes over the same time intervals by the same amount. This value, equal to the ratio of the speed difference to the length of time, over which the speed has changed, is called acceleration. This number, showing how much the speed per unit of time has increased or decreased, can be large (then it is said that the body quickly gain or lose speed) or insignificant when the object accelerates or brakes more smoothly.

Acceleration, as well as speed, isphysical vector quantity. The acceleration vector along the direction always coincides with the velocity vector. An example of equally accelerated motion can be the case of a free fall of an object, in which the rate of incidence (the rate of attraction of an object by the earth's surface) changes per unit time by a certain amount, called the acceleration of gravity.

Uniform motion is theoretically possiblebe regarded as a special case of uniformly accelerated. Obviously, if the speed does not change with such motion, then acceleration or deceleration does not occur, hence, the acceleration value with uniform motion is always zero.