How to calculate the friction of guide rail
Publish: 2021-05-17 01:58:07
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there will be bitcoin chain and Ethereum chain when choosing the recharge address of the exchange. If you have a good choice, you can contact bitcom online customer service
2. Before calculating the friction force, we must first analyze the motion of the object to determine whether it is static friction or sliding friction. If it is sliding friction, the formula
F
can be used= μ N
calculation, where μ
is the friction coefficient; If it is static friction, it is usually solved according to the motion of the object (static, uniform motion, or variable speed motion) by using the equilibrium condition or the law of motion
to determine the direction of sliding friction, we must grasp the judgment basis of "the direction of sliding friction is opposite to the relative motion direction of the object". The specific method is: first select the object subject to friction as the research object, and then take the object in direct contact with the research object as the reference object, find out the speed direction of the research object relative to the reference object, then the direction of sliding friction is opposite to the direction of the relative speed
the basis for judging the direction of static friction is: "the direction of static friction is always tangent to the contact surface, and is opposite to the direction of relative motion trend of the object". The specific method is: firstly, select the object subject to static friction as the research object, and then select the object in contact with the research object as the reference object, and then assume that the contact surface is smooth to judge the velocity direction of the research object relative to the reference object, that is, the relative motion trend direction. Then, the direction of static friction is opposite to the direction of relative motion trend.
F
can be used= μ N
calculation, where μ
is the friction coefficient; If it is static friction, it is usually solved according to the motion of the object (static, uniform motion, or variable speed motion) by using the equilibrium condition or the law of motion
to determine the direction of sliding friction, we must grasp the judgment basis of "the direction of sliding friction is opposite to the relative motion direction of the object". The specific method is: first select the object subject to friction as the research object, and then take the object in direct contact with the research object as the reference object, find out the speed direction of the research object relative to the reference object, then the direction of sliding friction is opposite to the direction of the relative speed
the basis for judging the direction of static friction is: "the direction of static friction is always tangent to the contact surface, and is opposite to the direction of relative motion trend of the object". The specific method is: firstly, select the object subject to static friction as the research object, and then select the object in contact with the research object as the reference object, and then assume that the contact surface is smooth to judge the velocity direction of the research object relative to the reference object, that is, the relative motion trend direction. Then, the direction of static friction is opposite to the direction of relative motion trend.
3. 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
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
4. 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
, where 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.
the calculation formula of sliding friction is f
= μ N
, where 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. The reasons for the problem are as follows:
1
2. The TCP / IP settings of the computer setting the router are correct. The router is connected to adslmodem. Because the modem settings conflict with the default settings of the router, it is unable to enter the router settings page
3. The router is used in the existing network, which is 192.168.1.0 network segment, the same as the router's LAN network
4. Proxy server is set in browser
5. The computer setting the router uses multiple network cards, and the TCP / IP setting of the network card is wrong;
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2. The TCP / IP settings of the computer setting the router are correct. The router is connected to adslmodem. Because the modem settings conflict with the default settings of the router, it is unable to enter the router settings page
3. The router is used in the existing network, which is 192.168.1.0 network segment, the same as the router's LAN network
4. Proxy server is set in browser
5. The computer setting the router uses multiple network cards, and the TCP / IP setting of the network card is wrong;
6. Unknown_Error
7. The problems and reasons of early reading
1. The development of all aspects is not mature, and its reading activities are often blind and random. Part of the reason is that teachers ignore the guidance of children, part is the relationship between the age characteristics of children themselves
2. Correct view of early childhood reading
although many families have realized that early childhood reading plays a very important role in children's development, they can not correctly understand and grasp the real value and meaning of early childhood reading and lack scientific understanding. In the specific guidance process, it is overemphasized that reading activities are used as a means or tool for children to obtain information and knowledge. Many parents think that "children's reading is beneficial to the development of children's intelligence", but they seldom realize the role and value of early reading in children's emotional development, habit formation, ability cultivation, etc. Some parents even equate children's reading with early literacy. As a result, in the process of reading guidance, parents put too much energy on mechanical literacy, utilitarian pursuit of literacy, one-sided knowledge, learning "tool" reading. However, it ignores the cultivation of children's overall reading ability, reading interest and reading habits. Such reading is incomplete and even harmful
3. Teachers lack correct guidance in the process of reading
in kindergartens, teachers often lack correct guidance in children's reading. Too much pursuit of the "results" of reading guidance makes children's reading lose its own charm, and children's reading activities become a rigid ecational behavior, weakening children's interest in reading. On the other hand, in the specific guidance process, some teachers do not know enough about the development characteristics of children's reading ability, do not take into account the way and characteristics of children's acceptance in the reading process, can not carry out targeted guidance, can not effectively mobilize children's interest and desire in reading, improve the quality of reading. For example: some teachers in guiding children to read books, just read according to the text on the book, do not pay attention to those pictures matching with the text, also ignore the problems and confusion raised by children in the process of reading. A thick book may be read for children in a few minutes, but they turn a blind eye to all kinds of information in the picture. So, children in such a reading process only get some single information, and did not really enjoy the fun and value of reading. In addition, some teachers do not understand children's reading characteristics and needs. In the analysis and evaluation of children's behavior in the process of reading, we often can't give proper analysis, can't stand in the position of children to analyze their behavior, easy to make subjective judgment, in some cases, it will hurt children's interest in reading and psychological development, so that the teacher and child reading which should be harmonious communication will become the burden of mechanical reading
4. The requirements for the rules of the book area are not clear
in kindergarten, teachers often make unclear requirements for the rules of the book area. Some children take several books at a time and read them together. Some children talk loudly with their peers while reading. Teachers rarely participate in children's reading, usually let children "sheep" reading.
1. The development of all aspects is not mature, and its reading activities are often blind and random. Part of the reason is that teachers ignore the guidance of children, part is the relationship between the age characteristics of children themselves
2. Correct view of early childhood reading
although many families have realized that early childhood reading plays a very important role in children's development, they can not correctly understand and grasp the real value and meaning of early childhood reading and lack scientific understanding. In the specific guidance process, it is overemphasized that reading activities are used as a means or tool for children to obtain information and knowledge. Many parents think that "children's reading is beneficial to the development of children's intelligence", but they seldom realize the role and value of early reading in children's emotional development, habit formation, ability cultivation, etc. Some parents even equate children's reading with early literacy. As a result, in the process of reading guidance, parents put too much energy on mechanical literacy, utilitarian pursuit of literacy, one-sided knowledge, learning "tool" reading. However, it ignores the cultivation of children's overall reading ability, reading interest and reading habits. Such reading is incomplete and even harmful
3. Teachers lack correct guidance in the process of reading
in kindergartens, teachers often lack correct guidance in children's reading. Too much pursuit of the "results" of reading guidance makes children's reading lose its own charm, and children's reading activities become a rigid ecational behavior, weakening children's interest in reading. On the other hand, in the specific guidance process, some teachers do not know enough about the development characteristics of children's reading ability, do not take into account the way and characteristics of children's acceptance in the reading process, can not carry out targeted guidance, can not effectively mobilize children's interest and desire in reading, improve the quality of reading. For example: some teachers in guiding children to read books, just read according to the text on the book, do not pay attention to those pictures matching with the text, also ignore the problems and confusion raised by children in the process of reading. A thick book may be read for children in a few minutes, but they turn a blind eye to all kinds of information in the picture. So, children in such a reading process only get some single information, and did not really enjoy the fun and value of reading. In addition, some teachers do not understand children's reading characteristics and needs. In the analysis and evaluation of children's behavior in the process of reading, we often can't give proper analysis, can't stand in the position of children to analyze their behavior, easy to make subjective judgment, in some cases, it will hurt children's interest in reading and psychological development, so that the teacher and child reading which should be harmonious communication will become the burden of mechanical reading
4. The requirements for the rules of the book area are not clear
in kindergarten, teachers often make unclear requirements for the rules of the book area. Some children take several books at a time and read them together. Some children talk loudly with their peers while reading. Teachers rarely participate in children's reading, usually let children "sheep" reading.
8. Mining license mainly includes: development and utilization plan, safety and health special chapter, feasibility study, energy saving evaluation report,
comprehensive treatment of geological environment, land reclamation plan, water resources demonstration report, water and soil conservation plan, etc.
comprehensive treatment of geological environment, land reclamation plan, water resources demonstration report, water and soil conservation plan, etc.
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