Does support count

1. Supporting force is the force of one object on the contact surface of another. The supporting force can be represented by the symbol "n" Normal force)
object exerting force: the object exerting force (the earth) the object under force: the object under force note: the object exerting force is also the object under force (because the force between objects is mutual) and has mutual characteristics
supporting force is not gravity
gravity is vertical downward
supporting force is the force given to an object by the supporting surface

2. If an object or a part to be examined keeps moving or stationary in a straight line at a constant speed, the supporting force is equal to the resultant force of all the other forces, and the direction is the same
otherwise, f = ma is used

3. Not necessarily, that is, when the state changes, support is not equal to pressure. For example, when walking in the desert, support is not always equal to pressure, but only when the foot is on the bottom, support is equal to pressure. Because when you don't step on the bottom, the pressure makes the sand move and work, and there is no selfless conversion of reaction force and selfless conversion of support force, so the support force is not equal to the pressure before you step on the bottom. For example, bungee jumping, if support equals pressure, it can't proce take-off. Diving athletes, and so on, as long as the state is changing, support may not be equal to pressure. So support doesn't always equal pressure.

4. It is the reaction force of pressure
for example, when the wood is quickly placed on the table, the wood block gives the table a pressure, and the table gives the wood block a supporting force. The two are opposite but collinear, and the size is equal
both supporting force and pressure are proced by the deformation of the object, and they are elastic in nature

5. You can always say it according to different standards. In fact, it is not contradictory.
in the case that only gravity and elasticity work, the mechanical energy of the system is conserved, so such a force is called "conservative force"

push-pull extrusion is the same force, which means that the force between two objects pushing, pulling and squeezing each other is elastic
it is said from different angles

6. According to the nature of the force, there is only gravity, elastic force, friction force (excluding electromagnetic part)
according to the effect of the force, there are tension, centripetal force and so on

7. Certainly, the pressure and supporting force are interaction forces, so the magnitude must be equal
both forces are perpendicular to the surface of the object
hope to adopt, don't understand.

8.

Yes

There are many situations in which gravity and supporting force are not equal, such as objects resting on an inclined plane. In fact, in the case of equal gravity and supporting force, when the external force is not considered, only when the object is placed on the horizontal plane. When you squeeze an object against a vertical wall, gravity has nothing to do with support

The force exerted on an object by the attraction of the earth is called gravity. The force exerted by gravity is the center of the earth. The direction of gravity is always straight down. The weight of an object is proportional to its mass

the force that can make an object gain weight is not only gravitational force, but also inertial force. Because they all act on every element of matter at the same time. Therefore, the concept of gravity is promoted to: the combined action of universal gravitation and inertial force that can make an object gain weight is called gravity. This is the depth of the concept of gravity after ascension

when expounding the concept of supporting force, it is always said that one object has supporting force for another, then the latter is the stressed object, and the point of action should be marked on the stressed surface (sometimes for the sake of beauty and preciseness, the point of action is on the center of gravity of the object). If a wooden block is placed on a horizontal table and is supported by the desktop, the point of action of supporting force should be marked on the center of gravity of the wooden block

extended data:

the direction of the supporting force is always perpendicular to the surface of the object (supporting surface) and points to the direction of the stressed object

gravity is not equal to the earth's gravity on objects. Due to the rotation of the earth itself, except for the two poles, all objects on the ground move around the earth's axis at approximately uniform speed. This requires a centripetal force perpendicular to the earth's axis. This centripetal force can only be provided by the earth's gravity on the object

the centripetal force of the object is very small, so it can be approximately considered that the gravity of the object is equal to that of the universal gravitation, and the influence of the earth rotation can be omitted. The gravity component of gravity provides the acceleration of gravity, and the centripetal force component of gravity provides the centripetal acceleration to keep the rotation of the earth

For an object with uneven mass distribution, the position of the center of gravity is related not only to the shape of the object, but also to the mass distribution in the object. The center of gravity of the truck changes with the loading amount and loading position, and the center of gravity of the crane changes with the weight and height of the lifting object

The position of the center of gravity is of great significance in engineering. For example, when the crane is working, if the center of gravity is not appropriate, it is easy to overturn; If the center of gravity of a high-speed rotating wheel is not on the shaft, it will cause intense vibration. Increasing the support surface of the object and recing its center of gravity will help to improve the stability of the object

9. In a broad sense, elastic force includes supporting force and pulling force, which is one of the four major forces of mechanics
elasticity and pressure are a pair of balance forces, and supporting force and pressure are interaction forces
there is no direct relationship between supporting force and pulling force. The specific situation is analyzed in detail
supporting force, pressure and pulling force are named after their effects on objects.