Do magnets count power
Publish: 2021-04-21 01:50:41
1. Calculation formula of magnetic field intensity: H = n × I / Le
where h is the intensity of magnetic field, and the unit is a / m; N is the number of turns of the excitation coil; I is the excitation current (measured value), unit a; Le is the effective magnetic circuit length of the test sample, in M
calculation formula of magnetic inction: B= Φ / ( N × AE)
where B is the magnetic inction intensity, and the unit is WB / m ^ 2; Φ Is the inced magnetic flux (measured value), in WB; N is the number of turns of the inction coil; AE is the effective cross-sectional area of the test sample, in m ^ 2.
where h is the intensity of magnetic field, and the unit is a / m; N is the number of turns of the excitation coil; I is the excitation current (measured value), unit a; Le is the effective magnetic circuit length of the test sample, in M
calculation formula of magnetic inction: B= Φ / ( N × AE)
where B is the magnetic inction intensity, and the unit is WB / m ^ 2; Φ Is the inced magnetic flux (measured value), in WB; N is the number of turns of the inction coil; AE is the effective cross-sectional area of the test sample, in m ^ 2.
2. The current situation of tourism development in Tianjin
1. The characteristics of human tourism resources are obvious, and the natural tourism resources are relatively scarce
Tianjin is one of the four municipalities directly under the central government of China, an open international port city along the coast, and the largest economic and Trade Center in northern China. It is not only a famous historical and cultural city in China, a tourist city with rich resources and profound connotation, but also an international port city full of modern vitality. Tianjin is rich in human tourism resources and has its unique characteristics“ From Qin and Han history to Shaanxi, from Ming and Qing history to Beijing, and from modern history to Tianjin. ". Tianjin is the epitome of modern Chinese history. There are many precious historical sites, former residences of celebrities and multi-national buildings. For example, Dagukou fort, Tianhou palace, le temple, Shiqu garden, Huo Yuanjia's former residence, Shijia courtyard and ancient church all embody the modern characteristics of Tianjin. The form of Tianjin concession is complete and the architectural styles are diverse, which is prominently shown as the well preserved small western style buildings on the "five roads", which is known as the "architectural museum". The existing former residences and style buildings of celebrities have distinctive national characteristics and traces of the integration of Chinese and Western cultures. These historical sites truly record the track of social development and evolution in Tianjin and even in China. They are the epitome and powerful witness of modern urban history and modern Chinese history, and they are also effective resources to promote the development of tourism in Tianjin. In addition, Tianjin's unique folk organ: Yangliu youth painting, clay figurine Zhang's clay figurine, relish food, Tianjin opera, Tianjin People's hospitality, all attract domestic and foreign tourists
although Tianjin is close to the Bohai Sea and has coastal artificial baths, amusement parks and resorts in the East, it does not have obvious advantages in the Bohai Rim tourism area. In contrast, the coastal scenery of Beidaihe, Qing and Dalian is more attractive to the tourists who yearn for the sea. The north is rich in natural tourism resources. For example, Panshan national scenic spot, Huangyaguan Great Wall, Jiulongshan National Forest Park, Baxianshan National Nature Reserve, Cuiping Lake scenic spot and other scenic spots dot the north gate of Tianjin. In addition, Haihe scenic line has also added the style of an international metropolis to Tianjin. However, compared with other regions with rich natural resources in China, Tianjin's natural tourism resources are not well-known and small in scale, which makes it difficult to form a regional comparative advantage< In order to create a good tourism environment and conditions, the construction of urban infrastructure should be relatively developed, especially the transportation instry closely related to passenger transport. Tianjin has now formed a port centered land, sea and air transportation system. There are more than 300 bus routes in the urban area; The completion of the light rail will connect the coastal development zone with the urban area more closely; The newly-built modern land stickers have changed people's travel mode and eased the urban traffic pressure; The half-hour journey of Beijing Tianjin urban rail will add more convenience to the exchanges between the two cities; In 2007, 17 international luxury cruise ships came to Tianjin port; Tianjin Binhai International Airport is one of the first-class air ports in China. At present, there are more than 30 routes at home and abroad
Tianjin has a population of more than 10 million, ranking 16th in the latest world urban population ranking. It covers an area of 11919.7 square kilometers, with a population density of more than 900 people / square kilometers, and the urban population density is even higher. The problems in the development of big cities also exist in Tianjin: traffic congestion, housing shortage, three wastes pollution, insufficient urban green area, urgent need to improve the urban ecological environment and residents' quality. Although Tianjin has done a lot of work in urban construction and transformation, and has made remarkable achievements, it is still far from the goal of a modern international tourism city, and its charm needs to be further strengthened
3. Among the characteristic tourism, coastal tourism is the most eye-catching, but the overall brand effect is not prominent. In 2007, the tourism department further explored the city's tourism resources to create a cultural tourism destination with distinctive characteristics in the north and even in the whole country. The city's 12 tourism theme plates and 7 tourism gathering areas surrounded by river, sea, mountain and lake heritage folk tourism, launched a series of tourism activities, In particular, the coastal tourism project has achieved fruitful results. According to the survey, the coastal area received 7.1215 million tourists, with a comprehensive tourism income of 5.988 billion yuan, an increase of 15.7% and 13.2%, ranking among the top in the whole area. However, the tourism instry is a fully competitive instry with the characteristics of low market access and poor concentration. The fierce competition of tourism yellow pages leads to the loss of some enterprises. Due to the lack of expansion and development, Tianjin's long context, many special natural geography, rich and colorful tourism resources have not been fully utilized, and Tianjin's tourism brand has not been established and highlighted< The second plenary session of the ninth session of Tianjin municipal Party committee put forward the idea of building three tourism systems: urban tourism, leisure tourism and business exhibition tourism. The establishment of the guidelines has made clear the direction of Tianjin tourism, but the city tourism image should be further strengthened, striving to play its own characteristics, forming a landmark, and reshaping a distinctive image in the public mind
the internal structure of Tianjin tourism instry needs to be improved in scale and adjusted in level. Compared with other provinces and cities in China, there are fewer large-scale tourism backbone enterprises with low influence. However, the tourism enterprises of one province and city play a leading role in driving the tourism development of the city. Compared with Beijing and Shanghai, the strength of travel agencies and the number of hotels have a certain distance, and there is also a small gap in the scale of scenic spot enterprises. However, the limitation of scale restricts the development of tourism instry, and cannot form the benefit of instrial amplification< Secondly, the Countermeasures of tourism development in Tianjin
1. Strengthen the construction of urban tourism environment and create an international tourism atmosphere
in the tourists' personal experience, the general environment of urban tourism will greatly affect the tourists' perception and overall evaluation of urban tourism. Therefore, the construction of urban tourism environment is as important as the development of tourism resources, and even can be regarded as an attractive urban tourism resource. But the general air quality, the poor quality of urban health environment, the lack of hospitality of residents, the weak sense of service, and the low taste of the city are the true portrayal of Tianjin's tourism environment. Tourism environment has become an important factor restricting the development of international tourism in Tianjin. Therefore, Tianjin should attach great importance to the construction of urban comprehensive environment, strengthen environmental management, urban greening and universal ecation, and constantly improve the environmental quality, so as to make the urban comprehensive environment show full hospitality, realize the hospitality of style, facilities, citizens and ecology, and turn Tianjin into a city that can enter, stay, appreciate, enjoy and enjoy A memorable international tourist destination
2. Highlight the brand of multi-cultural compatibility, and do a good job in the development and utilization of tourism resources
Tianjin culture contains palace culture, water transport culture, port culture, folk culture and foreign culture, which has the characteristics of far compatibility. The rich connotation of these cultures and the beautiful picture of Jingu culture will make Tianjin tourism market unique and fascinating. Efforts to transform cultural resources into distinctive tourism resources and ultimately build a city brand are the focus of strategic adjustment of our city. In 2007, Tianjin municipal government held a municipal tourism work conference, emphasizing "developing tourism, making full use of various tourism resources, deeply developing a series of tourism procts, creating cultural tourism brands such as" Tianjin in modern China ", speeding up the construction of tourist attractions, scenic spots and leisure bases, expanding regional tourism cooperation, and cultivating tourism as an important instry." This has further pointed out the direction for the sound and rapid development of Tianjin's tourism
there are many kinds of tourism resources and great potential for development and utilization. The development of tourism resources should take the construction of coastal urban tourism as the goal, highlight the characteristics of famous historical and cultural cities and modern port cities, and vigorously promote the development and construction of 12 tourism blocks of "seeing Tianjin in modern China". At present, eight tourism blocks have been basically completed: "old City Jinyun", "Yangliu ancient town", "old residence of Puyi", "charm of European continent", "small station training", etc "Jinwei cradle", "Yiao style", "Dagu cloud"; Through the protection and repair of the original tourism resources and cultural relics of the eight tourism plates, as well as the construction of new landscapes such as embankments, parks and sculptures, the development of Haihe River will form eight distinctive scenic areas or sightseeing belts with the theme of "seeing Tianjin in modern China" and one Haihe River as the main axis, reflecting the political, economic, cultural and cultural development of modern Tianjin The history of architecture and international communication. There are four sections that are being further improved and launched: "Westernization tracing", "Oriental Paris", "Rhine town" and "Financial Street". The new achievements of Tianjin's urban development and construction should be transformed into new tourism procts in a timely manner. With "new Tianjin, new style and new landscape" as the publicity theme, eight series of tourism procts, including Haihe new look tour, coastal scenery tour, mountain and wild scenic spot tour, red memory Tour, famous Museum Expo tour, famous residence tour, famous street leisure tour and folk culture tour, should be integrated and launched
3. Establishing the concept of international tourism and cultivating the image of international tourism metropolis
concept internationalization is the most important aspect of the international tourism system. Only when we are open-minded and have a sense of international development can we promote the development of Tianjin's tourism instry. Tianjin should strive to realize the uniqueness of its city and tourism management. On the premise of comprehensive consideration of the world competition pattern and development trend, Tianjin should identify and shape the strategic key advantages that affect the current and future urban tourism competitiveness from the perspective of internationalization. In addition, it is necessary to form a sense of great tourism, great linkage and great benefit, strengthen horizontal cooperation, develop Tianjin's tourism instry with its own resources, traffic location, market potential and historical and cultural conditions, strengthen writing with Beijing and Dalian, exchange information, share tourist resources, complement each other's advantages, and strive to realize the dislocation development of tourism with Beijing and Bohai rim
tourism image is a new field of urban tourism development, and it is difficult for a city without a unique and integrated tourism image to attract tourists for a long time. Tianjin has not yet formed a distinctive city tourism image, and has no competitive advantage in the domestic and international tourism market. Therefore, it is necessary to carry out the overall planning of Tianjin's tourism, accurately position, establish a unique image of the city's tourism, and avoid the decline of the city's tourism attraction e to the high degree of functional homogeneity. Tianjin's "11th Five Year Plan" tourism development plan puts forward the positioning of "distinctive coastal city tourism and leisure center city" and the overall image slogan of "Vientiane Tianjin, leisure city", which basically summarizes the characteristics of Tianjin's tourism. However, it still needs to deeply explore the positioning differences between Tianjin and other internationally famous tourism cities such as Hong Kong, Dalian and Hangzhou, Emphasis on uniqueness and sensationalism
4. Optimize the structure of tourism instry and take the road of group development
with the expansion of tourism instry scale and the change of tourist source structure of tourism market in Tianjin, the development of tourism instry in Tianjin has entered a transformation period“ During the Eleventh Five Year Plan period, Tianjin's tourism instry should stride forward to a big and strong tourism city. Tianjin's tourism instry stands at a new starting point and faces a new situation,
1. The characteristics of human tourism resources are obvious, and the natural tourism resources are relatively scarce
Tianjin is one of the four municipalities directly under the central government of China, an open international port city along the coast, and the largest economic and Trade Center in northern China. It is not only a famous historical and cultural city in China, a tourist city with rich resources and profound connotation, but also an international port city full of modern vitality. Tianjin is rich in human tourism resources and has its unique characteristics“ From Qin and Han history to Shaanxi, from Ming and Qing history to Beijing, and from modern history to Tianjin. ". Tianjin is the epitome of modern Chinese history. There are many precious historical sites, former residences of celebrities and multi-national buildings. For example, Dagukou fort, Tianhou palace, le temple, Shiqu garden, Huo Yuanjia's former residence, Shijia courtyard and ancient church all embody the modern characteristics of Tianjin. The form of Tianjin concession is complete and the architectural styles are diverse, which is prominently shown as the well preserved small western style buildings on the "five roads", which is known as the "architectural museum". The existing former residences and style buildings of celebrities have distinctive national characteristics and traces of the integration of Chinese and Western cultures. These historical sites truly record the track of social development and evolution in Tianjin and even in China. They are the epitome and powerful witness of modern urban history and modern Chinese history, and they are also effective resources to promote the development of tourism in Tianjin. In addition, Tianjin's unique folk organ: Yangliu youth painting, clay figurine Zhang's clay figurine, relish food, Tianjin opera, Tianjin People's hospitality, all attract domestic and foreign tourists
although Tianjin is close to the Bohai Sea and has coastal artificial baths, amusement parks and resorts in the East, it does not have obvious advantages in the Bohai Rim tourism area. In contrast, the coastal scenery of Beidaihe, Qing and Dalian is more attractive to the tourists who yearn for the sea. The north is rich in natural tourism resources. For example, Panshan national scenic spot, Huangyaguan Great Wall, Jiulongshan National Forest Park, Baxianshan National Nature Reserve, Cuiping Lake scenic spot and other scenic spots dot the north gate of Tianjin. In addition, Haihe scenic line has also added the style of an international metropolis to Tianjin. However, compared with other regions with rich natural resources in China, Tianjin's natural tourism resources are not well-known and small in scale, which makes it difficult to form a regional comparative advantage< In order to create a good tourism environment and conditions, the construction of urban infrastructure should be relatively developed, especially the transportation instry closely related to passenger transport. Tianjin has now formed a port centered land, sea and air transportation system. There are more than 300 bus routes in the urban area; The completion of the light rail will connect the coastal development zone with the urban area more closely; The newly-built modern land stickers have changed people's travel mode and eased the urban traffic pressure; The half-hour journey of Beijing Tianjin urban rail will add more convenience to the exchanges between the two cities; In 2007, 17 international luxury cruise ships came to Tianjin port; Tianjin Binhai International Airport is one of the first-class air ports in China. At present, there are more than 30 routes at home and abroad
Tianjin has a population of more than 10 million, ranking 16th in the latest world urban population ranking. It covers an area of 11919.7 square kilometers, with a population density of more than 900 people / square kilometers, and the urban population density is even higher. The problems in the development of big cities also exist in Tianjin: traffic congestion, housing shortage, three wastes pollution, insufficient urban green area, urgent need to improve the urban ecological environment and residents' quality. Although Tianjin has done a lot of work in urban construction and transformation, and has made remarkable achievements, it is still far from the goal of a modern international tourism city, and its charm needs to be further strengthened
3. Among the characteristic tourism, coastal tourism is the most eye-catching, but the overall brand effect is not prominent. In 2007, the tourism department further explored the city's tourism resources to create a cultural tourism destination with distinctive characteristics in the north and even in the whole country. The city's 12 tourism theme plates and 7 tourism gathering areas surrounded by river, sea, mountain and lake heritage folk tourism, launched a series of tourism activities, In particular, the coastal tourism project has achieved fruitful results. According to the survey, the coastal area received 7.1215 million tourists, with a comprehensive tourism income of 5.988 billion yuan, an increase of 15.7% and 13.2%, ranking among the top in the whole area. However, the tourism instry is a fully competitive instry with the characteristics of low market access and poor concentration. The fierce competition of tourism yellow pages leads to the loss of some enterprises. Due to the lack of expansion and development, Tianjin's long context, many special natural geography, rich and colorful tourism resources have not been fully utilized, and Tianjin's tourism brand has not been established and highlighted< The second plenary session of the ninth session of Tianjin municipal Party committee put forward the idea of building three tourism systems: urban tourism, leisure tourism and business exhibition tourism. The establishment of the guidelines has made clear the direction of Tianjin tourism, but the city tourism image should be further strengthened, striving to play its own characteristics, forming a landmark, and reshaping a distinctive image in the public mind
the internal structure of Tianjin tourism instry needs to be improved in scale and adjusted in level. Compared with other provinces and cities in China, there are fewer large-scale tourism backbone enterprises with low influence. However, the tourism enterprises of one province and city play a leading role in driving the tourism development of the city. Compared with Beijing and Shanghai, the strength of travel agencies and the number of hotels have a certain distance, and there is also a small gap in the scale of scenic spot enterprises. However, the limitation of scale restricts the development of tourism instry, and cannot form the benefit of instrial amplification< Secondly, the Countermeasures of tourism development in Tianjin
1. Strengthen the construction of urban tourism environment and create an international tourism atmosphere
in the tourists' personal experience, the general environment of urban tourism will greatly affect the tourists' perception and overall evaluation of urban tourism. Therefore, the construction of urban tourism environment is as important as the development of tourism resources, and even can be regarded as an attractive urban tourism resource. But the general air quality, the poor quality of urban health environment, the lack of hospitality of residents, the weak sense of service, and the low taste of the city are the true portrayal of Tianjin's tourism environment. Tourism environment has become an important factor restricting the development of international tourism in Tianjin. Therefore, Tianjin should attach great importance to the construction of urban comprehensive environment, strengthen environmental management, urban greening and universal ecation, and constantly improve the environmental quality, so as to make the urban comprehensive environment show full hospitality, realize the hospitality of style, facilities, citizens and ecology, and turn Tianjin into a city that can enter, stay, appreciate, enjoy and enjoy A memorable international tourist destination
2. Highlight the brand of multi-cultural compatibility, and do a good job in the development and utilization of tourism resources
Tianjin culture contains palace culture, water transport culture, port culture, folk culture and foreign culture, which has the characteristics of far compatibility. The rich connotation of these cultures and the beautiful picture of Jingu culture will make Tianjin tourism market unique and fascinating. Efforts to transform cultural resources into distinctive tourism resources and ultimately build a city brand are the focus of strategic adjustment of our city. In 2007, Tianjin municipal government held a municipal tourism work conference, emphasizing "developing tourism, making full use of various tourism resources, deeply developing a series of tourism procts, creating cultural tourism brands such as" Tianjin in modern China ", speeding up the construction of tourist attractions, scenic spots and leisure bases, expanding regional tourism cooperation, and cultivating tourism as an important instry." This has further pointed out the direction for the sound and rapid development of Tianjin's tourism
there are many kinds of tourism resources and great potential for development and utilization. The development of tourism resources should take the construction of coastal urban tourism as the goal, highlight the characteristics of famous historical and cultural cities and modern port cities, and vigorously promote the development and construction of 12 tourism blocks of "seeing Tianjin in modern China". At present, eight tourism blocks have been basically completed: "old City Jinyun", "Yangliu ancient town", "old residence of Puyi", "charm of European continent", "small station training", etc "Jinwei cradle", "Yiao style", "Dagu cloud"; Through the protection and repair of the original tourism resources and cultural relics of the eight tourism plates, as well as the construction of new landscapes such as embankments, parks and sculptures, the development of Haihe River will form eight distinctive scenic areas or sightseeing belts with the theme of "seeing Tianjin in modern China" and one Haihe River as the main axis, reflecting the political, economic, cultural and cultural development of modern Tianjin The history of architecture and international communication. There are four sections that are being further improved and launched: "Westernization tracing", "Oriental Paris", "Rhine town" and "Financial Street". The new achievements of Tianjin's urban development and construction should be transformed into new tourism procts in a timely manner. With "new Tianjin, new style and new landscape" as the publicity theme, eight series of tourism procts, including Haihe new look tour, coastal scenery tour, mountain and wild scenic spot tour, red memory Tour, famous Museum Expo tour, famous residence tour, famous street leisure tour and folk culture tour, should be integrated and launched
3. Establishing the concept of international tourism and cultivating the image of international tourism metropolis
concept internationalization is the most important aspect of the international tourism system. Only when we are open-minded and have a sense of international development can we promote the development of Tianjin's tourism instry. Tianjin should strive to realize the uniqueness of its city and tourism management. On the premise of comprehensive consideration of the world competition pattern and development trend, Tianjin should identify and shape the strategic key advantages that affect the current and future urban tourism competitiveness from the perspective of internationalization. In addition, it is necessary to form a sense of great tourism, great linkage and great benefit, strengthen horizontal cooperation, develop Tianjin's tourism instry with its own resources, traffic location, market potential and historical and cultural conditions, strengthen writing with Beijing and Dalian, exchange information, share tourist resources, complement each other's advantages, and strive to realize the dislocation development of tourism with Beijing and Bohai rim
tourism image is a new field of urban tourism development, and it is difficult for a city without a unique and integrated tourism image to attract tourists for a long time. Tianjin has not yet formed a distinctive city tourism image, and has no competitive advantage in the domestic and international tourism market. Therefore, it is necessary to carry out the overall planning of Tianjin's tourism, accurately position, establish a unique image of the city's tourism, and avoid the decline of the city's tourism attraction e to the high degree of functional homogeneity. Tianjin's "11th Five Year Plan" tourism development plan puts forward the positioning of "distinctive coastal city tourism and leisure center city" and the overall image slogan of "Vientiane Tianjin, leisure city", which basically summarizes the characteristics of Tianjin's tourism. However, it still needs to deeply explore the positioning differences between Tianjin and other internationally famous tourism cities such as Hong Kong, Dalian and Hangzhou, Emphasis on uniqueness and sensationalism
4. Optimize the structure of tourism instry and take the road of group development
with the expansion of tourism instry scale and the change of tourist source structure of tourism market in Tianjin, the development of tourism instry in Tianjin has entered a transformation period“ During the Eleventh Five Year Plan period, Tianjin's tourism instry should stride forward to a big and strong tourism city. Tianjin's tourism instry stands at a new starting point and faces a new situation,
3. We call the property that objects can attract iron, cobalt, nickel and other substances magnetism. Since magnetism is a property that magnets can attract paramagnetic materials, it is determined by the properties of magnets. Magnetic force is a kind of interaction force. There is no magnetic force in the magnet itself. It is the result of the interaction between two magnets, which can be expressed as repulsive force and gravitational force. They just attract each other, not force
4. There are four basic interactions in nature. The interaction between magnets belongs to electromagnetic interaction, and the interaction between molecules belongs to gravitational interaction
5. You can calculate the balance of force. A magnet is used to attract the iron nail, one end of the light rope is used to cover the iron nail, and the other end is connected with a spring dynamometer. If in the vertical direction, the attraction of the magnet is equal to the spring dynamometer indication minus the nail's gravity. Of course, e to the existence of air resistance and other factors, this method has a certain error
6. The repulsive force between permanent magnets can hardly be calculated by general methods. Although the virtual displacement method can be used for single value simulation calculation, few people are willing to do so.
here is a calculation formula:
F= μ 0/[4S(H/ δ)^ 2]
μ 0 is the vacuum permeability, h is the magnetomotive force of the permanent magnet, s is the surface area of the permanent magnet, δ Is the air gap
here is a calculation formula:
F= μ 0/[4S(H/ δ)^ 2]
μ 0 is the vacuum permeability, h is the magnetomotive force of the permanent magnet, s is the surface area of the permanent magnet, δ Is the air gap
7. Suction and repulsion are the same. There is no absolutely accurate formula, because it is very complex to calculate the suction and repulsion. Just like the magnetic field distribution on the surface of a magnet, it is necessary to obtain the average magnetic field strength on the surface to calculate the suction more accurately, which requires finite element analysis. The calculation formula is f = 4.14 * B & # 178* A where f, N, B are the average flux density (not remanence) of the adsorption surface, kgs, a is the area of the adsorption surface, CM & # 178;, This is a more accurate formula in my opinion.
8.
Let the air gap magnetic density BG, magnetic field strength Hg, air gap area Ag and air gap length LG, then the attractive force F is:
F = BG * Hg * Ag / 2
that is, the magnetic force between the magnet and the armature is proportional to the air gap magnetic density, magnetic field strength and air gap area. See the following
for details
9. The magnetic force of NdFeB magnet is 640 times of its own weight, that is to say, it can absorb 640 times of its own weight&# 160; In general, NdFeB magnets can absorb objects 600 times their weight. Because there are many specifications and shapes of NdFeB magnets, such as magnets with holes and special-shaped magnets, which are directly related to the suction, the calculation is more complex. Here we only list two simple specifications: round and square< br /> &# 160; Example: square NdFeB magnet, brand: N35, specification: 30mm × 15mm × 5mm, magnet suction calculation formula: magnet volume × density × 600 (multiple)
& 160&# 160; 1、 Magnet density: the density of N35 is about 7.5g/cm3&# 160; 2、 Magnet weight: Volume × Density (30mm) × 15mm × 5mm × 0075 = 16.875g
& 160&# 160; 3、 Magnet suction: 16.875 × 600 = 10125g
& 160&# 160; It can be seen that a 30mm × 15mm × A 5mm square magnet can hold about 10.1kg of objects< br /> &# 160; Another example: a 20 mm * 5 mm N35 NdFeB magnet
, # 160&# 160; Suction = (10 radius * 10 radius * 3.14 * 5 thickness) volume * 0.0075 density * 600 times = 7065g (g), that is to say, 20 * 5 N35 magnet can absorb 7.065kg object< br /> &# 160; If your magnet specifications are of these two specifications, you can directly apply the formula to calculate. It should be noted that the dimension unit is mm (mm), not this unit, which needs to be converted< br /> < br /> &# 160; Calculation formula of magnetic force with permanent magnet f = bilsin θ< br /> &# 160; F is the magnetic force, also known as ampere force, B is the magnetic inction, I is the current in the wire, l is the length of the wire, θ F = MH, where m is the strength of the magnetic pole and H is the strength of the magnetic field. The strength of the magnetic field proced by the magnetic pole is inversely proportional to the third power of the distance R
& 160&# 160; 1、 Magnet density: the density of N35 is about 7.5g/cm3&# 160; 2、 Magnet weight: Volume × Density (30mm) × 15mm × 5mm × 0075 = 16.875g
& 160&# 160; 3、 Magnet suction: 16.875 × 600 = 10125g
& 160&# 160; It can be seen that a 30mm × 15mm × A 5mm square magnet can hold about 10.1kg of objects< br /> &# 160; Another example: a 20 mm * 5 mm N35 NdFeB magnet
, # 160&# 160; Suction = (10 radius * 10 radius * 3.14 * 5 thickness) volume * 0.0075 density * 600 times = 7065g (g), that is to say, 20 * 5 N35 magnet can absorb 7.065kg object< br /> &# 160; If your magnet specifications are of these two specifications, you can directly apply the formula to calculate. It should be noted that the dimension unit is mm (mm), not this unit, which needs to be converted< br /> < br /> &# 160; Calculation formula of magnetic force with permanent magnet f = bilsin θ< br /> &# 160; F is the magnetic force, also known as ampere force, B is the magnetic inction, I is the current in the wire, l is the length of the wire, θ F = MH, where m is the strength of the magnetic pole and H is the strength of the magnetic field. The strength of the magnetic field proced by the magnetic pole is inversely proportional to the third power of the distance R
10. This is a very complex problem, so I won't mention it before high school, even college physics doesn't have it (college physics only has the calculation method of magnetic field generated by current, but magnet doesn't), unless it is a related major.. This is related to some properties of the magnet itself, the shape of the magnet, the magnetic medium in the middle (whether there is ferromagnetic material in the middle), and whether there is magnetization. There may be some empirical formulas for magnets with fixed shape and strength
I only know how to calculate the torque of the motor. As for me, I think it's difficult to calculate the torque of the motor for non related majors. It's more complicated because only very close can there be a force. If it's very close, it's necessary to carry out triple integral calculation according to the shape. It's very troublesome, and it's even more difficult to calculate if the shape is irregular....
I only know how to calculate the torque of the motor. As for me, I think it's difficult to calculate the torque of the motor for non related majors. It's more complicated because only very close can there be a force. If it's very close, it's necessary to carry out triple integral calculation according to the shape. It's very troublesome, and it's even more difficult to calculate if the shape is irregular....
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