What are the equilibrium conditions of an object under the action of a co point force?

If several forces have the same point of action, or if the lines of action (or reverse extensions) intersect at one point, these forces are called common point forces

Equilibrium conditions for co-point forces.

From Newton's second law, we know that when the resultant force on the object is zero, the acceleration is zero, and the object will remain at rest or move in a uniform straight line, that is, the object is in equilibrium, therefore, the equilibrium condition of the object under the action of the common point force is that the net force is zero, that is, <>

Object equilibrium conditions.

1) Equilibrium: The object is in a state of stationary or uniform linear motion.

If an object remains at rest or moves in a straight line at a uniform speed under the action of a common point force, we say that the object is in equilibrium.

It follows that there are two types of equilibrium states:

One is static equilibrium, where the velocity of the object is v=0 and the acceleration of the object a=0;

The other state is dynamic equilibrium, where the velocity of the object is v≠0 and the acceleration of the object is a=0

2) The object is in equilibrium, and its force must meet the net external force of zero, that is, f = 0, acceleration = 0This is the equilibrium condition of the object under the action of the co-point force.

I forgot, I remember asking the teacher before, and the teacher just said"When the object starts to move, the dynamic force is large and the resistance, and then the car moves at a constant speed when the 2 forces reach the equilibrium state, Newton's first law says that when the object is subjected to a pair of equilibrium forces, the object is in a state of rest or uniform motion, which cannot be proved by experiments, and is the result of abstract deduction"I know that, and I hope you get useful information from it

1) Objects moving in a straight line at rest or at a uniform speed, subjected to an external force.

Zero. 8 6f=0 or 8 6fx=0 8 6fy=0 Corollary: [1] If three non-parallel forces act on an object and are balanced, then the three forces must have something in common.

2] Several common point forces act on the object to equilibrium, in which the resultant force of any few forces is the remaining force.

The net force of a force must be equal to the opposite.

2) The equilibrium condition of the object with a fixed axis of rotation: the algebraic sum of the moment is zero Moment: m=fl (l is the arm of force, which is the vertical distance from the axis of rotation to the line of action of the force).

No, to keep an object in equilibrium, it is only necessary that the net force acting on the object is zero years old, but it is not necessarily a common point force. For example, if a long wooden stick is applied to each end of a vertical upward force, the wooden stick is in equilibrium, and the three forces (gravity and two vertical upward forces) on the wooden stick are not at the same point.

If the object is in equilibrium under the action of three forces, then the three forces are not parallel and are at the same point. But under the action of multiple forces, it is not necessarily a block.

The equilibrium condition of the spring body under the action of the common point force is as follows: the resultant force of the external rubber force on the object is zero;

Therefore, the answer is: the net force of the external force next to the bridge of the object is zero

The equilibrium of an object under the action of a common point forceFirst, the state of equilibrium.

If the object remains at rest or moves in a straight line at a uniform velocity, then the object is in equilibrium It can be seen that there are two situations in equilibrium state: one is the static equilibrium state, at this time, the speed at which the object moves

The basic ideas and methods of problem solving:

The procedure for solving the equilibrium problem of an object is to determine the equilibrium body, make a force diagram, decompose it orthogonally, and orient the column equation

The first step is to determine the research object, according to the meaning of the object or node in equilibrium as the research object, usually use the isolation method to isolate the determined research object from the environment in which it is located, but sometimes the research object together with its related objects as a research system (holistic method), but the calculation is convenient, please pay attention to the example questions that will be given below

The second step is to carry out the force analysis and make the force diagram of the research object This step is the key to the success or failure of the problem, and it must be meticulous and thoughtful, no more and no omission (to judge whether the force of the analysis is correct, it can be dealt with by the hypothetical demolition method and the conditional method).

The third step is to establish a coordinate system or stipulate the positive direction How to establish a suitable coordinate system, it depends on the known and unknown quantities of the problem The principle is to make the angle between the force and the coordinate axis simple and clear, so that the equation can be bright and clear Improper setting of coordinates will cause the need to use the sum difference product in the missing angle of the three thoughts, the half-angle doubling formula and other operation tools, so that the calculation is very cumbersome Generally, it is advisable to choose the direction of the unknown quantity as the positive direction of the coordinate system, and after establishing the coordinate system, the force that is not on the coordinate axis is decomposed to the coordinate axis by orthogonal decomposition method. And draw an accurate diagram of its components for later use

The fourth step is to list the equilibrium equations according to the sufficient and necessary conditions of the equilibrium of the object, solve the calculations, evaluate the conclusions, and discuss the conclusions if necessary

If an object remains at rest or in a state of uniform linear motion under the action of several forces, then these forces are balanced, so the state at rest or in a uniform linear motion state is called an equilibrium state

When the object is in equilibrium, the forces are balanced, and the magnitude of a pair of equilibrium forces is equal and opposite in the opposite direction, and the net force acting on the same straight line is zero, so the effects cancel each other out

Answer: (1) The equilibrium state refers to the state in which the object remains at rest or in a uniform linear motion (2) The equilibrium condition of the object under the action of co-point force is equal in magnitude, opposite in direction, acting on the same straight line, and the resultant force is zero

The equilibrium condition of an object under the action of a common point force is that the net force experienced by the object is zero.

Two-force equilibrium: If the object is in equilibrium under the simultaneous action of two forces, then the two forces are equal in magnitude and opposite directions, and act on the same straight line, and their net force is zero, which is the two-force balance in junior high school.

Three-force equilibrium: The object is in equilibrium under the action of three common point forces, and the resultant force of any two forces is equal to the third force and opposite.

n force equilibrium: when the object is in equilibrium under the action of n non-parallel forces at the same time, n forces must be at the same point, and the net force is zero, which is called the equilibrium of n common point forces, in which the resultant force of any (n-1) force must be equal to the nth force, opposite, and act on the same straight line.

Solution Method:

First, the decomposition method.

When an object is in equilibrium under the action of three common point forces, any one of the forces is decomposed in the opposite direction of the other two forces, so that the three-force equilibrium problem is transformed into a two-force equilibrium problem in two directions, and a pair of forces in each direction is equal in magnitude.

2. Synthesis method.

For the balance of three forces, if any two of the three forces are combined into one force, the resultant force is balanced with the third force, and the balance of the three forces is transformed into a two-force balance problem.

3. Orthogonal decomposition method.

When an object is in equilibrium under the action of three or more forces, the equilibrium equation of orthogonal decomposition is commonly used: fx = 0, fy = 0. In order to facilitate the calculation, a coordinate system is established.

so that as much force as possible falls on the axes.

God laughs as a principle.

The two forces of interaction between the virtual grandchildren of the object (the source can) are balanced, because :

The action force and the reaction force occur at the same time, acting on the same straightness line, equal in magnitude, and in opposite directions.

Therefore they are a pair of equilibrium forces).