Ask a question about the balance of forces and leverage

1} There is no friction, only gravity, and the ground is facing its supporting force. Vertically, it is supported by gravity and the ground; No force in the horizontal direction

2} 3 forces, gravity, static friction along the inclined surface, supporting force on the object on the inclined surface.

3} Look at the length between the force and the rotating shaft (power arm), and the other side is the resistance arm.

It depends on the power arm and the resistance arm, when the power arm is greater than the resistance arm (L1 is greater than L2), it is the labor-saving lever, and if the power arm is smaller than the resistance arm (L1 is less than L2), it is the laborious lever. The premise is that the forces are the same.

A balanced lever (it doesn't have to be horizontal, as long as it doesn't move or keep moving at a constant speed):

Determine a fulcrum o (any point of force is fine, choose the best one).

There are exactly two forces f1 and f2 on the lever, and the length is L1 and L2 of the perpendicular line where F1 F2 is located, which is called power and resistance, power arm and resistance arm (in fact, it is artificially determined).

There is a relation: f1 l1 = f2 l2

When L1 L2, it is a labor-saving lever.

L1 L2 is, for the effort leverage.

1. When the lever rotates, there will be a point on the lever that is not moving, and the lever is rotating around it, then this point is the fulcrum.

2. The distance from the fulcrum to the power line is the power arm. As the saying goes, from the fulcrum to the straight line where the power is located to make a perpendicular line segment (to be at a 90-degree angle to the straight line where the power is located), this perpendicular line segment is the power arm.

3. The distance from the fulcrum to the resistance line is the resistance arm. As the saying goes, make a perpendicular segment from the fulcrum to the straight line where the resistance is located (at a 90-degree angle to the straight line where the resistance is located), and this perpendicular line segment is the resistance arm.

4. After making the power arm and the resistance arm, compare the size of the two, the lever of the power arm is greater than the resistance arm, the lever is labor-saving, and the lever of the power arm is less than the resistance arm.

4} The direction of gravity and friction is vertically downward, so it is greater than the original tension.

5} Interaction Force Condition: Mutual contact. There is an extrusion in between. Powerful effect.

The condition of the balance of the two forces: acting on a straight line. The magnitude of the force is equal. In the opposite direction.

1.Be. 2.Vertical downward gravity, perpendicular to the support force of the box, parallel to the upward friction of the inclined face.

3.The point that intersects --- chopsticks.

4.Small, this question lacks conditions, 5 conditions for the balance of two forces: acting on a straight line. The magnitude of the force is equal. In the opposite direction.

Equilibrium Force: Several forces acting on the same point, the vector sum of which is 0, is a set of equilibrium forces. To put it simply, for two forces, if they are equal in magnitude and opposite directions, acting on the same object, then the two forces are a pair of balanced forces.

Two-force balance: An object is acted on by two forces and remains at rest or in a state of uniform linear motion, these two forces are a pair of balanced forces, called two-force balance. That is to say:

If an object remains at rest or in a straight line at a uniform speed, the force on it must be a balanced force (or no force)".

Equipoise first proposes that the essence of the two concepts is different. The action force and the reaction force describe the law of action between two objects, A has a strong effect on B, and B must also have a strong effect on A; Two-force equilibrium describes the characteristics of two forces in which an object is in equilibrium under the action of two forces.

Secondly, the nature of the two forces is the same, either gravity, elastic force, friction and so on. However, the equilibrium of two forces is not, as long as the two forces are satisfied to act on the same object, equal in magnitude, in opposite directions, and acting in the same straight line, it is a balanced force, regardless of the nature of the two forces.

The re-action force and the reaction force are simultaneous, generating at the same time, changing at the same time, and disappearing at the same time; Two-force balance does not have this characteristic.

1. Equilibrium force An object is acted on by several forces at the same time, and if it remains at rest or in a state of uniform linear motion, we say that these forces are balanced. (The net force experienced by this object is 0) 2. Conditions for the equilibrium of two forces Two forces acting on the same object, if equal in magnitude, are in opposite directions and are in the same straight line.

If an object can remain at rest or move in a straight line at a uniform speed when it is subjected to two forces, we say that the object is in equilibrium.

f + f = f (f = f )].

Two forces acting on the same object at the same time on the same straight line, if the object remains at rest or in a uniform linear motion, then the effect of these two forces on the motion of the object cancels each other out (the net force is 0), we say that the two forces are balanced.

1] Conditions for the balance of two forces:

Magnitude: Equal Direction: Opposite Two forces act on the same object and in the same straight line.

Effect: The object remains stationary or moves in a straight line in either direction.

Two forces acting on the same object are balanced against each other if they are equal in magnitude, opposite in direction, and in the same straight line.

When an object is in a state of stationary or uniform linear motion under the action of several forces, we say that the object is in equilibrium. When the object is in equilibrium under the action of two forces, we say that the two forces are in equilibrium with each other, which is referred to as the equilibrium of two forces.

Two forces equilibrium is a two-force equilibrium when two forces of equal magnitude and opposite directions are applied to an object at the same point, always keeping the object at rest or moving in a straight line at a uniform speed.

The same object is acted on by 2 forces.

And these two forces are equal in magnitude and opposite in direction (if the object cannot be seen as a particle, the two forces must act on the same point).

If an object can remain at rest or move in a straight line at a uniform speed when it is subjected to two forces, we say that the object is in equilibrium. The two forces that keep an object in equilibrium are called equilibrium forces. Two forces act on an object, and if the object is at rest or in a state of uniform linear motion, then the effects of these two forces cancel each other out, and we say that these two forces are balanced.

The magnitude of the condition for the equilibrium of the two forces: equal direction. Such as: vertical upward support force and vertical downward gravity. At this point, the object is stationary or moving in a straight line at a uniform speed.

Comparison of Equilibrium and Acting Forces:

When judging whether the two forces on an object are a pair of balanced forces, we must first see whether the two forces act on the same object, and then see whether the other three conditions are met at the same time; It is also possible to see whether the object remains at rest or moves in a straight line at a uniform speed under the action of these two forces.

In the movie "Captain America 2", the director of S.H.I.E.L.D. is hunted and killed by the Hydra organization. Nick drives a car that resembles a tank and goes all the way. Bucky dropped a bomb under the chassis of the car, and the bomb**, the car's uniform speed and straight driving state were instantly subverted.

So how can you keep an object moving in a straight line at a uniform speed?

1. Definition of two-force balance:

Two forces acting on an object, if the object is at rest or in a state of uniform linear motion, then the effects of these two forces cancel each other out, and we say that these two forces are balanced.

2. Conditions for the balance of two forces:

Size: Equal.

Direction: Opposite two forces act on the same object, and on the same straight line, the two forces balance the effect: the object remains at rest or moves in either direction to do a uniform linear motion.

That is, two forces acting on the same object, if they are equal in magnitude, opposite in direction, and on the same straight line, the two forces balance each other.

Science 2 Forces Equilibrium Condition 1

Two-force equilibrium means that an object is in equilibrium (stationary or uniform linear motion) under the action of two forces, then the two forces are in balance.

Equilibrium conditions: Two forces acting on the same object, equal in magnitude, opposite in direction, and two forces in a straight line: The equilibrium conditions of two forces are summarized in four words: "one, equal, anti, one".

Newton's Second Law:

Contents: The object will produce acceleration under the action of the resultant external force, and the direction of acceleration is the same as the direction of the resultant external force, and the magnitude of the acceleration is proportional to the magnitude of the resultant external force and the inverse proportion of the inertial mass of the object.

The second law quantitatively describes the effect of the force acting on and quantitatively measures the magnitude of the inertia of an object. It is vector and is an instantaneous relation.

It should be emphasized that the combined external force on the object will produce acceleration, which may change the motion or velocity of the object, but this change is related to the motion state of the object itself.

In a vacuum, since there is no air resistance, various objects have the same acceleration regardless of their mass because they are only subjected to gravity. Therefore, in free fall, their velocity changes the same in the same time interval.

The two forces are more similar: equal in magnitude in opposite directions acting on a straight line at different points: equilibrium forces acting on an object can be forces of different natures; Mutual forces acting on different objects are forces of the same nature.

If an object is in equilibrium under the action of two forces, then the two forces are in balance with each other, referred to as two-force equilibrium. The conditions for the equilibrium of the two forces are: equal in magnitude, opposite in direction, acting on a straight line, acting on the same object.

An object is said to be in equilibrium if it can remain at rest or move in a straight line at a uniform speed when it is subjected to two forces. The two forces that put the object in equilibrium are called equilibrium forces, and the two forces act on the object, and if the object is at rest or in a state of uniform linear motion, the effects of these two forces cancel each other out, and the two forces are said to be balanced. The size of the condition of the balance of the two forces:

equal directions; Opposite effects; On the same straight line, two forces acting on the same object on the same object, if the magnitude is equal and the direction is opposite, and on the same straight line, the two forces are balanced with each other, and an object can be subjected to multiple forces, such as: vertical upward support force and vertical downward gravity, etc., at this time the object is stationary or does uniform linear motion.

Man stands on the ground.

Balance of forces: the gravitational force on which people are subjected and the support force of the ground towards people.

Interaction forces: the pressure of people on the ground and the support of the ground towards people.

Electric lights on the wall.

2. Force balance: the gravitational force received by the electric light and the pulling force of the rope on the electric light.

Interaction force: the tension of the lamp on the rope and the tension of the rope on the lamp.

Books placed on the table.

Two-force balance: the gravitational force received by the book and the support force of the table for the book.

Interaction Force: The pressure of the book on the table and the support force of the table on the book.

Anything like this is fine.

The key point is: the condition for the equilibrium of two forces is: forces acting on the same straight line, on the same object, equal in magnitude, and in opposite directions.

An interaction force is: a force acting on the same straight line, equal in magnitude and in opposite directions, acting on two different objects.