The acting force acts on two different objects respectively, and the balancing force acts on the same object; The acting force must be of the same nature, but the balance is not necessarily; The acting force on different objects can't cancel each other out, but the balancing force can cancel each other out. The acting force has an instantaneous corresponding relationship, but the balancing force has no such corresponding relationship; The acting force only involves two interacting objects, and the balancing force involves three objects.
Expand one's knowledge
If an object is in a state of static or uniform linear motion under the action of several forces, and the effects of these forces cancel each other out, we say that these forces are in equilibrium.
The action of force is mutual. As long as one object exerts a force on another, the stressed object will definitely exert a force on the stressed object in turn. Simply summarized as: different action points, equivalence, inversion and collinearity. A pair of interaction forces must be generated and disappeared at the same time.
brief introduction
According to modern physics, there are only four natural forces in the universe, namely gravity, electromagnetic interaction, strong interaction and weak interaction. Everything in nature is built by these four natural forces.
Gravity is a force that can not only bind galaxies together, but also make a needle fall. It is the weakest of the four basic forces. The greater the mass and the closer the distance between two objects, the greater the attraction between them. Many scientists believe that gravity is carried by particles called gravitons, but no one has found them in any experiments.
universal rule
For many years, physicists have tried to explain the motion of the universe with a single scientific theorem, and they are studying in the direction of "universal law". The "universal law" holds that all forces, such as gravity, electromagnetic force, strong nuclear force and weak interaction force, are interrelated, and points out that all subatomic particles may be produced by a basic particle.
Conditions for the establishment of interaction force
As long as one object exerts a force on another object, the stressed object will in turn exert a force on the object exerting the force. These two forces are equal in magnitude and opposite in direction, acting on two different objects on the same straight line. Simply summarized as: foreign body, equivalence, reverse, collinear. Interaction force A pair of interaction forces must be generated and disappeared at the same time.