How to calculate the direction of force
Publish: 2021-05-03 16:28:17
1. Who can't afford his hometown
2. It is not appropriate to combine all forces into a resultant force. The non copoint force can form a couple and make the object rotate, so it can't move the force arbitrarily along its action line. Where the point of action is
because the internal strain of rigid body is often regarded as "0", sometimes the non collinear force can be calculated by changing the action line slightly. Like cars. The supporting force of the car is on four wheels respectively, and the gravity can be combined into one, and the action point is on the center of gravity. The reason why we dare to calculate the supporting force as a force of equal magnitude in the opposite direction of gravity is that the car itself does not deform. You can imagine a jelly car with four supporting wheels
therefore, the resultant forces can not be combined casually. In principle, as long as they don't share the same points, they can't. But without considering the volume, or the rigidity of the object without considering the rotation, it can be synthesized at will - as long as the direction of action of the force is not changed and the point of action is taken at will. Don't mix these three situations
if you want to install a reasonable point of action, you can take the point where the line of action of the force intersects the object; If you don't care about the accuracy of the loading, just pick it up. However, under the condition of gravity, the center of gravity is generally taken as the point of action of resultant force, which is another matter if the center of gravity is not in the object
the directed line segment representation of force is artificial. If you change the unit, the length of the directed line segment will change. Therefore, it is meaningless to ask whether the intersection of the directed line segment is the intersection of the extension line
in the second question, the resultant force is not a real force, but an expression of effect. If you remember the definition, force is an action. The effect of resultant force itself does not exist, but proces the same effect. Common force is whether several functions have the same attribute. Common point means having this "common point" attribute, and non common point means not having such an attribute. Joint forces cannot participate in this judgment
two forces intersecting at one point may not be regarded as common forces. I copied it, too. Hope it works for you
because the internal strain of rigid body is often regarded as "0", sometimes the non collinear force can be calculated by changing the action line slightly. Like cars. The supporting force of the car is on four wheels respectively, and the gravity can be combined into one, and the action point is on the center of gravity. The reason why we dare to calculate the supporting force as a force of equal magnitude in the opposite direction of gravity is that the car itself does not deform. You can imagine a jelly car with four supporting wheels
therefore, the resultant forces can not be combined casually. In principle, as long as they don't share the same points, they can't. But without considering the volume, or the rigidity of the object without considering the rotation, it can be synthesized at will - as long as the direction of action of the force is not changed and the point of action is taken at will. Don't mix these three situations
if you want to install a reasonable point of action, you can take the point where the line of action of the force intersects the object; If you don't care about the accuracy of the loading, just pick it up. However, under the condition of gravity, the center of gravity is generally taken as the point of action of resultant force, which is another matter if the center of gravity is not in the object
the directed line segment representation of force is artificial. If you change the unit, the length of the directed line segment will change. Therefore, it is meaningless to ask whether the intersection of the directed line segment is the intersection of the extension line
in the second question, the resultant force is not a real force, but an expression of effect. If you remember the definition, force is an action. The effect of resultant force itself does not exist, but proces the same effect. Common force is whether several functions have the same attribute. Common point means having this "common point" attribute, and non common point means not having such an attribute. Joint forces cannot participate in this judgment
two forces intersecting at one point may not be regarded as common forces. I copied it, too. Hope it works for you
3.
Three solution function is needed to decompose all the forces into a coordinate system. It is only necessary to calculate the resultant forces of the forces in two directions perpendicular to each other and then synthesize them. As shown in the figure, the resultant forces in the horizontal and vertical directions are obtained respectively. FX and FY are obtained, and then FX is obtained by using the parallel quadrilateral rule and Pythagorean theorem, The size and direction of the resultant force of FY
0
4.
Three solution function is needed to decompose all the forces into a coordinate system. Just calculate the resultant forces of the forces in two directions perpendicular to each other and then synthesize them. As shown in the figure, calculate the resultant forces in horizontal and vertical directions respectively. FX and FY, and then use the parallelogram rule and Pythagorean theorem to find the magnitude and direction of the resultant forces of FX and FY
5. According to the momentum theorem, the impulse of the combined force is equal to the change of the object's momentum I = mv2-mv1. Given the final momentum and the initial momentum, we can calculate the impulse with the change of the force's size and direction by vector operation
6. Direction of resultant force of power and other forces
7. The acting point of the force can be connected with the rotation axis, and the force can be decomposed along the line direction and vertical line direction, and then the direction of the torque generated by the force can be judged. The moment of a force to a point is the physical quantity of the rotation action of a force to an object around a certain point, which is equal to the vector proct of the position vector of the force acting point and the force vector. For example, an object fixed at point o with a spherical hinge is subjected to the action of the instantaneous force F. the action point of F is a, R is the position vector of a, and the angle between R and F is α
if the object is at rest, it will rotate along a plane perpendicular to R and F and through the instantaneous axis of point O after the force F is applied. The magnitude of rotation is determined by rfsin α express. Because the instantaneous axis is directional, the moment of force F to point O is defined as a vector, which is expressed by m, that is, M = R × F The positive direction of M can be determined by the right hand rule
extended data
the effect of force on the rotation of an object is not only related to the magnitude of the force, but also related to the arm of force, that is, the effect of force on the rotation of an object is determined by the moment. When the arm is equal to zero, no matter how large the force is, it will not have a rotational effect on the object. When the force is parallel to the axis of rotation, there will be no rotation effect on the object. The key to calculate the torque is the force finding arm. The attention arm is the distance from the rotation axis to the action line of the force, not the distance from the rotation axis to the action point of the force
reference source: network torque
reference source: network torque balance
if the object is at rest, it will rotate along a plane perpendicular to R and F and through the instantaneous axis of point O after the force F is applied. The magnitude of rotation is determined by rfsin α express. Because the instantaneous axis is directional, the moment of force F to point O is defined as a vector, which is expressed by m, that is, M = R × F The positive direction of M can be determined by the right hand rule
extended data
the effect of force on the rotation of an object is not only related to the magnitude of the force, but also related to the arm of force, that is, the effect of force on the rotation of an object is determined by the moment. When the arm is equal to zero, no matter how large the force is, it will not have a rotational effect on the object. When the force is parallel to the axis of rotation, there will be no rotation effect on the object. The key to calculate the torque is the force finding arm. The attention arm is the distance from the rotation axis to the action line of the force, not the distance from the rotation axis to the action point of the force
reference source: network torque
reference source: network torque balance
8. In the experiment, the parallelogram can be drawn with the line segment representing the force. The diagonal line is the resultant force, and the two adjacent sides represent the component force. The size of the force is proportional to the length of the line segment. The size of the force can be known by measuring the length of the line segment
in the actual calculation process, it is mainly to draw parallelogram, and then use geometric knowledge to solve the problem. The triangle rule is essentially the same as the quadrilateral rule.
in the actual calculation process, it is mainly to draw parallelogram, and then use geometric knowledge to solve the problem. The triangle rule is essentially the same as the quadrilateral rule.
9. Generally speaking, there are only three functions
1. Help enterprises solve business pain points more efficiently, cope with complex business more calmly and track market changes more quickly
2. The release of bitcoin and Ethereum / fabric, two landmark milestones in the development of blockchain technology, has brought its decentralized, secure and tamperable attributes into the public's view, making it possible to solve many business problems
3. In recent years, we have made a detailed technical comparison of the mainstream blockchain technology platforms on the market, and found that there are still many problems in the application of these platforms in enterprises. Only enterprise level blockchain can cope with such a large amount of data and carry complex business system. Renren chain is building an enterprise level blockchain cloud service platform to solve these problems. Through one-stop integration, continuous delivery, data visualization and supporting multiple bottom layers, Renren chain can help enterprises realize out of the box use.
1. Help enterprises solve business pain points more efficiently, cope with complex business more calmly and track market changes more quickly
2. The release of bitcoin and Ethereum / fabric, two landmark milestones in the development of blockchain technology, has brought its decentralized, secure and tamperable attributes into the public's view, making it possible to solve many business problems
3. In recent years, we have made a detailed technical comparison of the mainstream blockchain technology platforms on the market, and found that there are still many problems in the application of these platforms in enterprises. Only enterprise level blockchain can cope with such a large amount of data and carry complex business system. Renren chain is building an enterprise level blockchain cloud service platform to solve these problems. Through one-stop integration, continuous delivery, data visualization and supporting multiple bottom layers, Renren chain can help enterprises realize out of the box use.
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