Interaction of bodies. Definition and types

Interaction is an action that is mutual. All bodies are able to interact with each other by means of mechanical motion, inertia, force, density of matter and, in fact, the interaction of bodies. In physics, the action of two bodies or a system of bodies on each other is called interaction. It is known that when the bodies converge, the character of their behavior changes. These changes are reciprocal. When the bodies are diluted to significant interaction distances, they disappear.

When the bodies interact, the result is always felt by all the bodies (after all, when something is affected, it always follows a payoff). Thus, for example, in billiards, when a cue hits the ball, the latter flies far more strongly than the cue, which is explained by the inertness of the bodies. The types and measure of the interaction of bodies are determined precisely by this characteristic. Some bodies are less inert, others more. The greater the mass of the body, the greater its inertia. The body, interacting changing its speed more slowly, has a greater mass and is more inert. The body, which changes its speed faster, has less mass and is less inert.

Strength is a measure that measures the interaction of bodies. Physics identifies four types of interactions that are not reducible to each other: electromagnetic, gravitational, strong and weak. Most often, the interaction of bodies occurs when they come into contact, which leads to a change in the velocities of these bodies in the inertial reference frame, which is measured by the force acting between them. So, to set in motion a stalled car, pushed by hands, it is necessary to exert force. If it is necessary to push it uphill, then it is much harder to do, because it will require a lot of force. The best option would be to apply force along the road. In this case, the magnitude and direction of the force are indicated (note that the force is a vector quantity).

Interaction of bodies is also under the influence of mechanical force, the consequence of which is the mechanical movement of bodies or parts thereof. Force is not the object of contemplation, it is the cause of motion. Every action of one body in relation to another manifests itself in motion. An example of the action of the mechanical force that generates motion is the so-called "domino effect". Skillfully placed dominoes fall one after another, passing the movement further along the row, if you push the first knuckle. There is a transfer of motion from one inert figure to another.

Interaction of bodies in contact can lead not only to the slowing or acceleration of their velocities, but also to their deformation - a change in volume or shape. A vivid example is a sheet of paper, compressed in his hand. Acting on it by force, we lead to an accelerated movement of parts of this sheet and its deformation.

Any body resists deformation when it is trying to stretch, squeeze, bend. From the side of the body, the forces that prevent it (elasticity) begin to act. The force of elasticity is manifested from the side of the spring at the time of its extension or contraction. The load, which is pulled on the ground by the rope, is accelerated, because the elastic force of the stretched cord acts.

Interaction of bodies during sliding along the surface separating them does not cause their deformation. In the case, for example, of sliding a pencil on a smooth surface of a table, skis or sledges on compacted snow, there is a force that prevents slipping. This is the force of friction, which depends on the properties of the surfaces of the interacting bodies and on the forces pressing them against each other.

Interaction of bodies can occur at a distance. The action of the forces of attraction, also called gravitational forces , occurs between all the bodies around, which can be noticeable only when the bodies have the dimensions of stars or planets. Gravity is formed from the gravitational attraction of any astronomical body and the centrifugal forces that are caused by their rotation. Thus, the Earth attracts the Moon, the Sun attracts the Earth, so the Moon circulates around the Earth, and the Earth, in turn, revolves around the Sun.

At a distance, electromagnetic forces also act. Despite the absence of touching any body, the compass needle will always rotate along the magnetic field line. An example of the action of electromagnetic forces is static electricity, which often appears on the hair when combing. The separation of charges on them is due to the frictional force. Hair, charging positively, begin to repel each other. Such statics often arise when putting on a sweater, wearing headdresses.

Now you know about the interaction of bodies (the definition turned out to be quite extensive!).