How to calculate friction force

1. You can't withdraw money, can you? help

2. The calculation method of sliding friction is different from that of static friction. When solving the friction, we must distinguish static friction from sliding friction.

I. calculation of sliding friction

1= μ FN calculation.

(1) according to the force condition of the object, calculate the positive pressure FN.

(2) according to the formula F= μ 2. Two force balance method: the object is in the state of equilibrium (uniform velocity, static positive), according to the two force balance conditions to solve; 2、 Calculation of static friction force

1. Balance condition method is used to solve static friction force. As shown in Fig. 3-3-19, a static object is placed on the horizontal plane. When a person pushes the object with horizontal thrust, the object is still. According to the two force balance condition, the static friction force is equal to the thrust force,

2, The value range of static friction is O & lt; F ≤ Fmax is independent of the positive pressure between objects, so the formula F cannot be used= μ FN solution.

3. Maximum static friction Fmax The value is equal to the external force along the contact surface when the object is just sliding, which is the maximum value of static friction and greater than sliding friction. Generally speaking, they are equal, and the maximum static friction is Fmax.. The formula is Fmax= μ Static FN, μ Static is the static friction coefficient and specific dynamic friction coefficient between objects μ Slightly larger

3. In the case of uniform motion, friction = traction
please adopt..

4. The formula of friction force has f only in high school= μ N
when calculating the size of friction, we should first judge whether the friction is sliding friction or static friction. And then it is solved by the corresponding method
the calculation formula of sliding friction is f= μ N. In the formula μ Dynamic friction coefficient, also called sliding friction coefficient, is only related to material and roughness of contact surface, but has nothing to do with contact area; N is the positive pressure

sliding friction: the force that occurs between two objects that contact each other and slide relatively, and prevents them from sliding relatively
the direction of friction is opposite to the direction of relative motion or the trend of relative motion. Instead of moving in the opposite direction of the object. Friction can be used as power or resistance.

5. To solve the problem of friction, you must understand the concept of friction, that is, the conditions under which friction occurs
the so-called friction is the force that hinders the relative motion of an object, and the direction of friction is opposite to the motion direction or relative motion direction of the object
the conditions of friction are: (1) two objects must contact each other 2) There is a squeeze between two objects 3) There is a tendency of motion or relative motion between two objects
1. When an object is stationary on a horizontal plane, if it is not pushed or pulled, it will not be affected by friction. If thrust or pull is received, it belongs to the category of static friction. The size of friction is equal to that of pull or thrust, and has nothing to do with the gravity or pressure of the object. Only the maximum static friction is related to the pressure or gravity on the object
2. If the object is pressed against the wall, the friction force is equal to the gravity of the object
3. As long as the object moves in a straight line at a constant speed on the horizontal plane, the object is subject to the action of balance force in the horizontal direction, that is, the thrust or pull force is equal to the friction force
4. If the object is not pushed by a force of 10N, the object is subjected to static friction, which is equal to the thrust. Just push with 15N force, and the friction force on the object is the maximum static friction force. If the thrust force is increased later, the friction force will not change. Theoretically, the sliding friction of objects is less than the maximum static friction, but it is generally considered that they are equal
5. Pull a 10N object with 15N force to move vertically and uniformly, then the friction force is f = 15-10 = 5N
if you understand my answer above, I think you will have a better understanding of friction force!

6. Friction can be divided into two types: static friction and sliding friction. There is no specific formula for calculating static friction. Usually, the force is balanced, that is to say, the static friction is generally received, and the objects are balanced (there are special ones). Therefore, the method of calculating the resultant force of other forces besides this friction force can be used, and the resultant force of other forces is equal to this friction force. For example, an object on the table with five n force to pull it, did not move, ask the friction is how much? The other resultant force of this problem is 5N, so the static friction force is 5N
there is a formula for calculating the sliding friction force, f = UF,
u is the dynamic friction coefficient, which is related to the contact surface, f is the positive pressure, which can be substituted in
so we need to distinguish the dynamic friction force from the static friction force before we can do the problem more accurately

7. Now mining is hot again. As a result, the price of graphics card increases, and that of second-hand ones also increases
if it's gtx10606g, the second-hand one is about 1700. If it's 3G, it's about 1300.