How to calculate the friction force of the inclined plane on the

1. When the object is placed on a rough inclined plane, when it is subjected to a force F in the direction of the inclined plane, which is greater than or equal to 100 n; When the force is equal to 40 n, the force in the direction of n is downward along the inclined plane; If the object is placed on the inclined plane, what is the friction force
first of all, it is greater than or equal to 100 cattle. The original question is that the size is equal to 100 cattle
secondly, make use of the sketch map given upstairs; Let G be the component of gravity in the inclined plane
when the pull force F = 100, the force balance in the inclined plane direction: the pull force F = friction force F + the inclined plane component force g of gravity; That is: when 100 = F + G
pulling force F = 40, the force in inclined plane direction is balanced, and pulling force F + inclined plane component of gravity g = friction force F; That is: 40 + G = f
the solution is f = 70 n

2. 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. The friction force is f = 15-10 = 5N when a 10N object is pulled by 15N

3. Let f be the upward force along the inclined plane, G be the downward component of gravity, and l be the friction force. Case 1: friction = 0
F = g
case 2: friction = f can be divided into two cases,
1: friction inclined plane is upward, and g = 2F
2: friction inclined plane is downward, and G + F = f leads to g = 0

4. What is the inclination of the slope θ， Then
mg
sin θ-μ mg
cos θ= Ma
it still depends on the conditions given by the title, calculate other unknowns, and get them from this formula μ

5. 1. Generally, objects slide on an inclined plane. In this case, you can use UF. Remember that f is a positive pressure
2. When an object slides at a constant speed without any other force, according to the balance of the force, the friction is equal to the sliding component of gravity.
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there are many other cases, which should be treated specifically. Remember that as long as the speed is constant, you can balance the force, If you have acceleration, you can use f = ma. If you know u and positive pressure F, you can use f = UF

7.

It's too much to generalize. To analyze specific topics, it is mainly based on the movement state of the block to analyze the force on the block. For example:

① the wooden block is stationary on the rough slope or slides at a constant speed

< p class = "ikqb_ image_ This is a state of equilibrium. The block is subjected to three forces: the gravity g = mg, and the supporting force of the inclined plane n = GCOS θ= mgcos θ， The friction f along the inclined plane upward

where f and the component force g of gravity g are downward along the inclined plane= mgsin θ It's balance

can also be used according to F= μ N= μ cos θ Come and ask

For example, on the basis of the above figure, a pull f is applied upward along the inclined plane to make the block slide upward with uniform acceleration, and the friction force on the block is downward along the inclined plane. In this case:

F = GSIN θ+ F (where f= μ N= μ Gcos θ)

e to the different forces, sliding trends and sliding directions on the inclined plane, the direction of friction on the block is different. It must be analyzed according to the specific subject conditions

9. Friction force = the component force perpendicular to the inclined plane generated by the force between the block and the inclined plane multiplied by the sliding friction coefficient between the two objects. What you call mechanical efficiency multiplied by tensile force is that only friction loses mechanical energy!