The greater the mass of the object, the greater the frictional force it is subjected to

Wrong. Friction = .fn ( is the friction factor, fn is the pressure of the contact surface) so the greater the pressure, the higher the friction factor, the greater the friction force.

For example: a block of iron of the same mass.

The friction of the iron on a horizontal cement surface is greater than that on a horizontal ice surface. The friction of iron on the horizontal cement surface is smaller than that on the "inclined plane". (fn level.)

The conditions under which friction arises are:

1. Objects are in contact with each other and the contact surface is rough;

2. There is a relative movement or relative movement tendency.

Points: 1. Sliding friction.

2. Friction.

Magnitude: Friction = .fn ( is the friction factor).

When the object slides on a rough horizontal plane, mg=fn, so there is more mass you think the greater the friction.

But if it is not sliding on a horizontal plane, then fn is not necessarily equal to mg, so it is not true.

That is, the magnitude of the frictional force is related to the product of fn and (friction factor).

If there is a premise for the force, the friction factor should also be considered.

It's not simply about mass, it's about positive pressure, and it's only when it's horizontal that gravity is equal to positive pressure, and there's also the coefficient of friction, which is proportional to positive pressure.

This question is discussed in terms of scores:

1. The object moves horizontally: the heavier the object, the greater the friction. Because the sliding friction experienced when moving on a plane is proportional to the positive pressure, the heavier the object, the greater the pressure on the supporting surface, and the greater the friction.

2. The object moves on an inclined plane: the heavier the object, the greater the friction. Same as above.

3. The object moves in the vertical direction, and the heavier the object, the greater the friction force. Because the air friction force on which an object moves in the air is related to the state and velocity of the object, and is not directly related to the weight of the object.

Because it can be seen from Newton's second law f=ma that when the force is constant, the greater the mass and the smaller the acceleration, the less the change in the motion state of the object, the greater the ability of the object to maintain its original motion state, which indicates that the greater the inertia of the object and vice versa

Visible mass is a measure of the magnitude of an object's inertia

The greater the mass, the greater the friction, or the friction does not increase, or even decreases, and there is no necessary connection between them

It is necessary to compare the difficulty of changing the state of motion with the same combined external force

The maximum static friction force of an object is always proportional to the weight of the object. （）

a.That's right. b.Mistake.

Correct answer to the case: a

When an object is placed on a horizontal plane and is only subjected to a horizontal external force, the amount of pressure on the supporting surface of the object is equal to the weight of the object. In this case, the heavier the object, the greater the frictional force experienced. When the pressure is completely independent of gravity, the magnitude of friction is independent of the magnitude of weight.

The force that hinders the relative motion (or relative tendency of motion) of an object 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.

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.

Friction has nothing to do with the weight of the object.

Friction is related to the amount of pressure on the object and the roughness of the contact surface. The greater the pressure, the rougher the contact surface of the object, and the greater the friction of the slip beam generated by the songtang.

The force that hinders the relative motion of an object is called frictional force. The direction of frictional force is opposite to the direction of the relative motion of the object. There are three types of friction force: static friction, rolling friction, and sliding friction.

The amount of friction depends on the roughness of the contact surface and the pressure of the sock stool between the contact surfaces, and the pressure is not necessarily related to the gravity of the object, for example, the pressure of the object placed on the vertical surface has nothing to do with gravity

So the answer is: false

Of course not.

The magnitude of friction is not directly related to gravity, or it is not necessarily related.

There are two conditions (factors) that really affect sliding friction--- roughness of the contact surfaces and the pressure between the contact surfaces.

The weight of the object does not necessarily affect the pressure between the contact surfaces, for example, the pressure between the eraser and the blackboard when erasing the blackboard has nothing to do with the weight of the eraser.

The amount of friction on an object can be related to the amount of gravity, or it may not be related. The key is to see if the amount of pressure is related to gravity.

Horizontally, the pressure is equal to the gravitational force, and the greater the pressure, the greater the gravitational force.

In the inclined direction, pressure is only a component of gravity and is related to gravity, but it is not equal to gravity.

Vertical orientation. The pressure is independent of gravity, and the magnitude of sliding friction is independent of the magnitude of gravity.

In the horizontal direction, the oblique upward force causes the object to move in a straight line at a uniform speed, and the component of the tensile force in the horizontal direction is a fixed value and equal to the magnitude of the sliding friction force.

When the tensile force changes, only the component force in the vertical direction can be changed, and if the component force in the horizontal direction is changed, it is impossible for the object to move in a uniform straight line. Because the sliding friction is a fixed value.

In this case, even if the tensile force changes, the inclination angle of the diagonal upward slope should be changed to maintain the component force in the horizontal direction.

On the same level, as long as the coefficient of friction is not zero, the greater the mass, the greater the friction. The horizontal plane and the inclined plane, it is definitely the inclined plane that has a greater pulling force.