The circle itself is initially a source of mysteries, as well as their extraordinary solutions. This figure is used as the most commonly used symbol of eternity. Often a circle is opposed to a square. The image of the wheel and circular motion are inextricably linked with the circle. In this process, the great minds of mankind not only saw the implementation of the laws of mechanics, but some philosophical meaning of a constant return to oneself.
In pre-Christian times, the sun-wheel sign was associated with the circle. Some thinkers saw in the circle the embodiment of an infinite line, and the movement of a point around a circle was an eternal process. Astrology in a circle saw a sign forming the line of the zodiac. Ouroboros - a snake that bites its tail, is it not just another symbol that indicates circular motion? Mathematicians and artists found a hidden meaning in this geometric figure, and physicists, studying the movement in a circle, created a powerful theoretical platform for explaining it by the standard laws of mechanics. In fact, it is curvilinear movement that is the most common. The movement of the body around the circle is a particular, ideal case of this diverse process.
Considering a curvilinear trajectory of movement, it can be represented as a set of arcs from circles of various radii. Accordingly, both circular motion and curved motion have acceleration. The movement always occurs under the influence of force, while there is a constant change in the direction of the velocity vector. The basic condition for curvilinear motion is that it is common for the body velocity vector and the force acting on it to be directed along straight lines that intersect. In contrast to rectilinear motion, the force and velocity vectors have the same direction.
If we consider even the uniform motion of the body in a circle, then we can distinguish its main properties and features. Firstly, this is an example of curvilinear motion with a constant modulus of speed. Secondly, do not forget that we are dealing with acceleration, which provokes a constant change of direction. This type of acceleration is called "centripetal." According to the classical definition, with this acceleration, the body moves in a circle at a speed constant in absolute value, and this acceleration is directed along the radius of the circle toward the center.
As for the velocity vector, here we are dealing with a quantity directed along the tangent to the trajectory. In the case of circular motion between the velocity vector and the acceleration vector, the angle is ninety degrees. Measuring the speed of a body moving in a circle, a standard value is used, which is the ratio of the distance traveled to time. With this approach, the distance traveled is nothing more than the length of the arc. Angular movement may also be used. In this case, a degree measure of the angle can be taken, at which the body will shift for a certain period of time, or it can be expressed in radians, or in relation to the length of the arc to the radius.
Given the constancy of the angular velocity during the circular motion of the body, it is worth considering several more quantities that characterize this process. This is the frequency and the period, being close values, the frequency is always inversely proportional to the period. In this case, we mean the time during which the body performs a full revolution, and the frequency is the number of revolutions per unit time interval.
The study of body motion in a circle is of great practical importance. Designing various machines and mechanisms is impossible without accurate calculations. And only thanks to the laws of mechanics, it is possible to carry out a fairly accurate calculation of various shafts, wheels, flywheels and other elements with which modern units and mechanisms abound.