The pressure is high, and the sliding friction is also large. Why?

First of all, you should have made a mistake in putting some heavy objects on A's body!

Pulling the rope is equivalent to tug-of-war, the key to winning lies in the size of the friction, the force of A pulling B and the force of B pulling A is the same, the friction is small and the one is easy to be pulled, A puts some heavy objects on the body, then the pressure of A on the ground is large, the friction of A is large, A is not easy to be pulled, A wins.

To explain that the pressure is high, the sliding friction is greater.

Sliding friction = kinetic friction factor positive pressure.

The kinetic friction factor is related to the material of the object and the roughness of the contact surface. As long as the physics problem and the contact surface remain the same, it will not change.

Therefore, the pressure is high, and the sliding friction is great! It's not clear where to go.

Put some heavy objects on the armor rope, then the armor rope will be heavier, and it will not be easy to be pulled.

Because f= fn

is a fixed value, so when fn increases, f also increases.

The macroscopic explanation may not be understood, but from the microscopic point of view, two objects with rough surfaces are pressed together, the so-called rough surface refers to the surface of the surface of a tiny protrusion or depression, the pressure will press the protrusions on the surface of the two objects into the depression, now if you want the two objects to slide relative to each other, you have to overcome the pressure, pull the protrusion out of the depression, the greater the natural pressure, the greater the resistance that needs to be overcome in sliding.

Sliding friction = slip coefficient * pressure.

The magnitude of friction is related to the following three factors:

1.Contact Surface RoughnessThe greater the roughness of the contact surface, the greater the friction between objects.

2.Pressure at the contact surface: The greater the pressure at the contact surface, the greater the friction.

3.Is it rolling, static, or sliding: Sliding friction and static friction produce more friction than rolling friction.

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. The direction of frictional force is opposite to the direction of the relative motion (or relative tendency of motion) of the object. There are three types of friction: static friction, rolling friction, and sliding friction.

There are two factors that affect the magnitude of friction:

1. The magnitude of friction is related to the pressure between the contact surfaces, and when the roughness of the contact surface is constant, the greater the pressure, the greater the friction.

2. The magnitude of friction is related to the roughness of the contact surface, when the pressure is constant, the rougher the contact surface, the greater the friction.

The friction between solid surfaces is divided into sliding friction, rolling friction, static friction, rolling friction and rotational friction. In engineering, lubricants are used to reduce friction.

If two surfaces rubbing against each other are separated by a layer of liquid, then liquid friction can occur between them, and mixed friction can occur if the liquid is not completely isolated.

The air cushion guide rail uses gas friction to work, and the working principle of both lubricating oil and air cushion guide rail uses "friction with liquid or gas (i.e. fluid) instead of solid friction" to work.

Summary. Hello, sliding friction will increase. In principle, the increase of pressure increases the degree of extrusion of the contact surface and increases the interaction force, which leads to an increase in friction.

When the normal pressure increases, what is the sliding friction.

Hello, the friction will increase when the sliding beat is moving. In principle, the increase of pressure makes the contact surface extrusion degree of the contact surface increase, the interaction force increases, and the friction force increases from the first He Heng.

Sliding friction refers to the force that hinders the movement of two objects that are pressed against each other when relative motion occurs;

Influencing factors of sliding friction: the magnitude of pressure and the roughness of the contact surface; The rolling friction is much less than the sliding friction;

The methods of increasing the friction are: when the roughness of the friction surface does not change, increase the pressure; When the pressure is constant, the roughness of the friction surface is increased; The object changes from rolling to sliding;

Answer: That's what I think in high school, f= n

Positive pressure refers to the pressure (elastic force) of the contact surface that produces sliding friction, and because it is perpendicular to the contact surface, many teachers call it positive pressure for emphasis.

Summary. The magnitude of the sliding friction is proportional to the pressure between the two objects, and the pressure between the two objects is represented by the symbol n, in order to represent the relationship between the pressure and the frictional force, we introduce a proportional coefficient , which is invariant for the fixed two frictions, which is called the kinetic friction factor, and the magnitude of the sliding friction force can be expressed by the formula f= n.

In order to represent the relationship between pressure and friction, we introduce a proportional coefficient, which is invariant for the fixed two frictions, called the dynamic friction factor, and the magnitude of the friction can be expressed by the formula f= n.

So how to explain this problem?

The direction of sliding friction is always opposite to the relative motion direction between objects, always hindering the relative motion between objects, and when the roughness is constant, the magnitude of sliding friction is proportional to the magnitude of pressure.

And what about the other way around?

The magnitude of the collapse of the sliding friction f is proportional to the positive pressure, i.e. f = n. is the dynamic friction factor: it is related to the material and roughness of the contact dough. The roughness of the contact surface is related to the elastic force between the contact surfaces.

Is the pressure proportional to the magnitude of the sliding friction (not the sliding friction and pressure)?

When the roughness is constant, the sliding friction is proportional to the pressure.