Gravity and friction cannot be a pair of action and reaction forces

No way. The action force and the reaction force are for two objects, and it is a system with only two forces on the object, for example, if you hit a wall with your fist, you give force to the wall, and the wall will give you a reaction force. Gravity and friction can only be given by the earth and the object providing friction, and then counting the stressed object itself, it is a system with 3 objects.

In fact, if the object is in equilibrium and there are no other forces, gravity and friction can only be a pair of equilibrium forces. Non-interacting forces.

No, gravity is the force between the earth and the objects around the earth, and its essence is gravitational force. The reaction force of gravity on an object is the attraction of the object to the earth, and the action of the force is reciprocal.

Whereas, friction is a force that is different in nature from gravity and arises when objects are in contact with each other and have relative motion or tendency. If A is subjected to the frictional force of B, then B is also subjected to the frictional force of A, and the two frictional forces are interaction forces.

In fact, two forces that interact with each other must be of the same nature, and the two forces exerting force are opposite to the force object.

Impossible Acting force and reaction force must be the same type of force Definition of interaction force: it must be a force of the same nature, and must act on two interacting objects and arise at the same time and disappear at the same time. You can lose friction, gravity can't.

When friction decreases, gravity does not become less with it.

Gravity and friction can only be equilibrium forces at best.

Equipoise references.

Impossible, the generation of friction must have a supporting force!! The direction of gravity is vertically downward, and if friction and gravity are a pair of acting and reacting forces, then the frictional force should be upward!! The support is horizontal!!

For example, if you press an object against a vertical wall!! But that's just Equipoise!! Action and reaction forces are defined as:

It must be a force of the same nature, and it must act on two interacting objects and arise and disappear at the same time. You can lose friction, gravity can't. When friction decreases, gravity does not become less with it.

No way. The action and reaction forces must be the same type of force

The essence of gravity is gravitational force.

Gravity is a gravitational force where two objects attract each other.

f=g*m1m2/（r*r）

The attraction of the earth to me and my attraction to the earth are a pair of acting and countering forces.

Friction: Two objects that are in contact with each other when they are going to take place or have been in relative motion. A force that hinders the relative motion is created on the contact surface, and this force is called friction.

So it's impossible.

Possibly, when an object is resting against a vertical wall, gravity and friction are a pair of acting and reacting forces.

Definition of interaction force: It must be a force of the same nature, and must act on two interacting objects and arise at the same time and disappear at the same time. You can lose friction, gravity can't. When friction decreases, gravity does not become less with it.

No way. What is Action vs. Reaction Force? I need to figure out the concept.

The action force and the reaction force disappear at the same time. Do you think it's possible for gravity to disappear? Even if gravity doesn't go away, is it possible that friction still exists? (In general, don't drill the tip of the horns).

Yes, for example, if you press a piece of wood against a rough, vertical wall, gravity and static friction are a pair of interacting forces.

If an object slides down a wall, isn't it subject to gravity and friction, isn't that action and reaction, I remember it seems, if it's wrong, I'm sorry

Well, the interacting force must be a force of the same nature. Gravity and friction are of different natures.

How can it. The force is acting on the other side.

Gravity acts on the object The object of force is the earth.

Friction acts on the wall The force applied is an object.

This is not in line with the requirements.

The first floor is about balance, don't talk nonsense if you don't understand. Lose face.

There is no direct relationship between friction and gravity; When the object is placed on a horizontal plane and there is no other external force, the pressure is equal to the gravitational force, i.e., the frictional force is equal to the pressure is equal to the gravitational force.

When objects are placed on an inclined plane, or sliding friction occurs between objects, according to the formula, the friction force is equal to the coefficient of friction multiplied by the pressure, that is, the friction force is related to the coefficient of friction and pressure, but not to gravity.

There are three types of friction: static friction, rolling friction, and sliding friction.

When an object slides on the surface of another object, friction occurs between the contact surfaces that hinders their relative motion, which is called sliding friction. The magnitude of sliding friction is related to the magnitude of the roughness of the contact surface and the magnitude of the pressure. The greater the pressure, the rougher the contact surface of the object, and the greater the sliding friction generated.

The methods of increasing the favorable friction are: increasing the pressure, increasing the roughness of the contact surface, and the magnitude of the pressure. The methods to reduce harmful friction are: reducing the pressure, smoothing the object from the contact surface, separating the object from the contact surface, changing the sliding to rolling, etc.

A pair of friction is not necessarily the action force and the reaction force, whether it is the action force and the reaction force, mainly depends on whether these points are satisfied

1.The size is equal, the direction is opposite, and it acts on a straight line.

2.Acts on different objects.

3.Creates and disappears at the same time.

4.The nature is the same.

The above 4 conditions must be met at the same time to confirm that a pair of forces is an action force and a reaction force, and the condition you give now only meets the 4th clause: the nature of the force is the same, so it cannot be determined.

The nature of the interacting forces must be the same. The so-called mutuality means that I give you and you give me. As you said, gravity, gravity is the attraction of the earth to the object, then its interaction force is the attraction of the object to the earth.

And the gravitational support force that the subject is talking about, such a force. These are two forces. One is gravity and the other is support.

The object is against the tabletop, there is pressure. The desktop has a supporting force against objects. The two forces are interacting.

They're all stretchy. It is caused by the elastic deformation of the contact surface surface.

Answer: Interaction forces.

The nature must be the same. As you can see from your problem description, you haven't really understood it yetInteraction forceswithEquipoiseThe difference.

Force is the action of an object on an object, and the force must occur between two objects, and there must be a reaction force at the same time as the acting force.

Thus, the action of force is reciprocal.

The object is attracted by the earth and is subjected to gravity, and the force exerted by the gravitational force experienced by the object is the earth. At the same time, the object will also give the same magnitude of reaction force to the earth, which is the interaction force between the object and the earth. Obviously, these pairs of interaction forces are of the same nature and are non-contact forces.

The force of the object being supported by the table and the pressure of the object on the table are the two interaction forces. This pair of interacting forces is a bouncy force. Whereas, the gravitational force experienced by the object and the supporting force of the table against the object are a pair of equilibrium forces.

The equilibrium force acts on the same object, while the interacting force is different bodies.

The two forces that interact must be forces of the same nature. Such as pressure and support, are elastic in nature.

Then you look at what the interaction force is. The interaction force is to interact, gravity is the gravitational force of the earth on the object, and the interaction force of gravity is naturally the gravitational force of the object to the earth, and has nothing to do with the supporting force. The pressure and support force of an object on the table is a pair of interacting forces.

The nature of the force cannot be divided by whether it is in contact or not. The example you give is not an interacting force, but a balancing force on an object. The nature of the interaction force must be the same, and in this example the pressure of the object on the table and the pressure of the table on the object are the interaction forces.

The interacting forces must be forces of the same nature.

Gravity and support are not interaction forces at all, but balance forces!

Please distinguish between the two concepts!

Gravity and support are not interacting forces, they are a pair of balancing forces. The support force of the object by the table and the pressure of the object on the table are a pair of interaction forces, both of which are contact forces and both belong to elastic force.

When an object is stationary on the tabletop, the table has a supporting force on the object, and the object also has a gravitational force on the tabletop, and both of them are in contact with each other.

It's not something that touches each other, is it? If that substance repels each other, they attract each other.

All forces are forces that arise between two objects and interact with each other.

Friction is also generated when an object moves (or has a tendency to move) relative to another object, A has friction against B, B also has friction against A, the two are equal in magnitude and opposite in direction, and are a pair of interaction forces.

For example, when block A slides to the right on the ground, the ground has a leftward friction on A and a rightward on the ground.

You can also do a simulation experiment with two hands to experience the existence of friction by sliding one hand forward along the other hand with both hands facing each other.

When two objects in contact with each other are in relative motion or have a tendency to move relatively, a force that hinders the relative motion or tendency to move on the contact surface is called friction.

Friction is a contact force, i.e., there can be friction between objects that are in contact with each other.

Friction generation conditions:

First, objects are in contact with each other;

Second, there is a mutual squeezing effect between objects;

Third: rough contact surface of the object;

Fourth, there is a tendency or relative motion between objects;

Classification of friction:

Static friction Rolling friction Sliding friction.

The magnitude of friction.

When at rest on the horizontal plane, the magnitude of the frictional force f=f The direction of the frictional force is opposite to the direction of the thrust (pull) force.

When sliding, the magnitude of the frictional force f= fn , fn refers to the positive pressure (not necessarily equal to the gravitational force of the object applying the force), and the direction of the frictional force is opposite to the relative direction of motion.

On an inclined plane. If the object is at rest on an inclined plane, the frictional force f =f1=mgsin direction is upward along the inclined plane.

If the object is moving on an inclined plane, the frictional force is the sliding friction f = f2 mgcos The direction of the frictional force is opposite to the relative direction of motion of the object.

The object is pressed against a vertical plane and the frictional force is independent of gravity.

In summary, the friction experienced by the block and the gravity of the block are not the same in the direction of the force, and the magnitude is not the same in all cases. Only when the object is on a plane and an inclined plane, there is a numerical relationship between the frictional force and the gravitational force. Hope it helps.

When a small piece of wood placed on a horizontal table is pulled in a straight line at a uniform speed, is the friction of the block the same as the gravity of the block?

Friction and gravity are not the same, there is a relationship, as follows:

f=μn（n=g）

If it's in the vertical direction:

Stationary or downward at a constant speed: f=g

The friction force of the wooden block placed on the horizontal plane is related to the gravity of the wooden block The nature of the contact surface is certain, the greater the gravity, the greater the pressure, and the greater the sliding friction

The sliding friction force is related to the nature of the contact surface (roughness) and is related to the pressure on the contact surface which can be expressed by the formula f= n.

n is the pressure and is not necessarily related to gravity.

The magnitude of friction is independent of gravity. Friction is divided into static friction and sliding friction, the magnitude of static friction is solved according to the equilibrium of force or Newton's second law, the magnitude of sliding friction is equal to the product of the kinetic friction factor and positive pressure, in this question you are asking, since the gravity and support force experienced by the object is equal in magnitude and opposite directions, and the supporting force received by the object is equal to the pressure of the object on the ground, so that the pressure is equal to the magnitude of gravity, but the force object is different, not the same force. The sliding friction force is multiplied by the dynamic friction factor by the pressure, which is different from the gravity force in both magnitude and direction.

In another scenario, if you press a wooden block against a vertical wall and let it accelerate or slow down, friction has nothing to do with gravity.

The frictional force of an object is related to the pressure and the roughness of the contact surface, whereas the gravitational force and pressure of an object on a horizontal plane are equal.

1. First of all, it should be made clear that force is the interaction between objects, and friction is also the interaction between objects, not the existence of an object. It is inaccurate to say "the frictional force of an object".

2. The magnitude of friction between objects is related to the roughness of the contact surface between objects and the pressure on the contact surface.

3. The dynamic friction factor reflects the roughness of the contact surface of the object, if n is used to represent the magnitude of the pressure, then the sliding friction between the objects f n, it can be seen that the rougher the contact surface and the greater the pressure, the greater the sliding friction between objects.

4. When the pressure on the contact surface is related to the gravity of the object, the magnitude of the friction force is related to the gravity of the object. For example, if an object is placed on a horizontal tabletop, the pressure on the table is equal to the gravitational force of the object, where f = n = g.

It should be noted that the pressure is not equal to the gravitational force of the object in all cases, and it is necessary to analyze the specific problem on a case-by-case basis.