Interaction is an action that is mutual. All bodies are able to interact with each other using 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 an interaction. It is known that when bodies approach each other, the nature of their behavior changes. These changes are mutual. When the bodies are separated at considerable distances, the interactions disappear.
When bodies interact, the result is always felt by all bodies (after all, when acting on something, a return always follows). So, for example, in billiards, when a cue hits a ball, the latter flies off much stronger than the cue, which is explained by the inertness of the bodies. Types and measure of interaction of bodies are determined by this characteristic. Some bodies are less inert, others more. The greater the mass of the body, the greater its inertia. A body that changes its speed more slowly during interaction has a larger mass and is more inert. A body that changes its speed faster has less mass and is less inertial.
Strength is a measure that measures the interaction of bodies. Physics distinguishes 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 frame of reference, which is measured by the force acting between them. So, in order to set in motion a stalled car, pushed by hands, it is necessary to apply force. If it needs to be pushed uphill, then it is much harder to do it, since this will require a lot of force. The best option in this case would be to apply a force directed along the road. In this case, the magnitude and direction of the force are indicated (note that the force is a vector quantity).
The interaction of bodies also occurs under the action of a mechanical force, the consequence of which is the mechanical movement of bodies or their parts. Force is not an object of contemplation, it is the cause of movement. Every action of one body in relation to another manifests itself in motion. An example of the action of a mechanical force that generates motion is the so-called "domino" effect. Artfully placed dominoes fall one after another, passing the movement further along the row if you push the first domino. There is a transfer of movement from one inert figure to another.
The interaction of bodies in contact can lead not only to a slowdown or acceleration of their speeds, but also to their deformation - a change in volume or shape. A striking example is a piece of paper clenched in the hand. Acting on it with force, we lead to the accelerated movement of parts of this sheet and its deformation.
Any body resists deformation when it is tried to stretch, compress, bend. From the side of the body, forces begin to act that prevent this (elasticity). The elastic force is manifested from the side of the spring at the moment it is stretched or compressed. A load pulled along the ground by a rope accelerates because the elastic force of the stretched cord acts.
The interaction of bodies during sliding along the surface separating them does not cause their deformation. In the case of, for example, a pencil sliding on a smooth surface of a table, skis or sleds on packed 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 force that presses them together.
Interaction of bodies can also occur at a distance. The action of attractive forces, also called gravitational forces, occurs between all the bodies around, which can be noticeable only when the bodies are the size of stars or planets. The force of gravity is formed from the gravitational attraction of any astronomical body and the centrifugal forces that are caused by their rotation. So, the Earth attracts the Moon to itself, the Sun attracts the Earth, so the Moon rotates around the Earth, and the Earth, in turn, rotates around the Sun.
Electromagnetic forces also act at a distance. Despite not touching any body, the compass needle will always turn along the magnetic field line. An example of the action of electromagnetic forces isstatic electricity, which often occurs on the hair when combing. The separation of charges on them occurs due to the force of friction. Hair, charging positively, begin to repel each other. Similar static often occurs when putting on a sweater, wearing hats.
Now you know what the interaction of bodies is (the definition turned out to be quite detailed!).
