Moment calculation of supporting force

1. In fact, it's force analysis, mainly to get the size of the resultant force. It's not always said that. The vertical direction is balanced, so only the horizontal direction is combined with the external force

2.

The moment of force is the physical quantity of the rotation of an object. It can be divided into moment of force to axis and moment of force to point. That is: M = lxf. Where l is the distance vector from the axis of rotation to the point of force and F is the vector force; The moment is also a vector

the moment of a force on an axis is the physical quantity that the force acts on an object to rotate about an axis, and its magnitude is equal to the proct of the component of the force on the plane perpendicular to the axis and the vertical distance from the line of action of the component to the axis. 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

extended data:

Properties of moment:

1. The moment of force F to point O is not only determined by the force, but also related to the position of moment center. The moment varies with the position of the moment center

When the force is zero or the arm of force is zero, the moment is zero

When the force moves along its action line, because the magnitude, direction and arm of the force do not change, the moment does not change

The algebraic sum of the moments of two mutually balanced forces at the same point is equal to zero

when an object is in static equilibrium, the static force is zero and the net moment to any point is zero. Moment is the derivative of angular momentum with time, just as force is the derivative of momentum with time. The angular momentum of a rigid body is the moment of inertia times the angular velocity

3.

M = f * l

where m is the moment of force F on the rotation axis O. if the object has the effect of anti clockwise rotation, it is defined as positive moment, otherwise it is negative moment

unit: in the international system of units, the unit of moment is Newton * meter, abbreviated as Newton * meter, symbol: n * m

in physics, moment refers to the tendency of force to make an object rotate around the axis of rotation or fulcrum. The unit of moment is Newton meter. The Greek letter is tau

The concept of

moment originated from Archimedes' research on lever. Rotational torque is also called torque or torque. Torque can change the rotational motion of an object. Pushing or pulling involves forces, while torsion involves moments. The moment is equal to the cross proct of the radial vector and the applied force

equilibrium conditions:

(1) the equilibrium of a body with a fixed axis of rotation means that the body is stationary or rotates uniformly around the axis of rotation

(2) the equilibrium condition of the object with fixed rotation axis is that the resultant moment is zero, that is, the sum of clockwise moment is equal to the sum of counter clockwise moment

General equilibrium condition:

the resultant force is zero and the resultant moment is zero at the same time, that is ∑ FX = 0, ∑ FY = 0, ∑ M = 0

torque:

(1) arm of force (L): the vertical distance from the rotation axis to the action line of force

(2) moment (m): M = L × F. The unit is n * M

(3) the moment describes the rotation effect of force on the object

(4) torque is a vector, only clockwise and counterclockwise directions are considered in middle school. It is usually specified that the torque is positive counterclockwise and negative clockwise

extended data:

according to the international system of units, the unit of energy and work is Joule, which is defined as 1 Newton meter. But Joule is not a unit of moment. Because energy is a scalar of the distance of the proct of the force points; The moment is the pseudo vector of the distance cross proct force. Of course, the same dimension is not only a coincidence; It takes 2 * PI joules of energy to apply a 1 N-M moment to a full revolution

when an object is in static equilibrium, the static force is zero and the net moment to any point is zero. For two-dimensional space, the requirement of balance is:

x, Y direction resultant force is 0, and resultant moment is 0

Properties:

1. The moment of force F to point O is not only determined by the force, but also related to the position of the moment center. The moment varies with the position of the moment center

When the force is zero or the arm of force is zero, the moment is zero

When the force moves along its action line, because the magnitude, direction and arm of the force do not change, the moment does not change

The algebraic sum of the moments of two mutually balanced forces at the same point is equal to zero

4. The moment is calculated by multiplying the force by the arm of force
the distance from the fulcrum of the lever to the straight line representing the force is called the arm of force. The arm of force is represented by a dotted line, which is not necessarily above the lever, and the moment is the force multiplied by the arm of force
levers can be divided into labor-saving lever, laborious lever and equal arm lever. Labor saving lever is labor saving, but it costs a lot of distance; Hard lever is hard, but it saves distance; And the equal arm lever, the two arms of force are equal, neither labor-saving nor laborious
I hope I can help you.

5.

Torque: the proct of the force and the arm of force is called the torque of the force on the axis of rotation

that is: M = f * l

where m is the moment of force F on the rotation axis O. any moment that causes the object to rotate in a counter clockwise direction is defined as a positive moment, and vice versa

Unit: in the international system of units, the unit of moment is Newton * meter, abbreviated as Newton * meter, symbol: n * m

< H2 > extended data

torque: the proct of force (f) and arm of force (L) (m). That is: M = f · L, When an object rotates around a fixed axis, there are only two possible directions for the torque, so it can be expressed by sign; Therefore, the resultant moment of several torques acting on a rotating body with a fixed axis is equal to their algebraic sum. This algebraic sum will determine whether the body is in equilibrium or non-equilibrium.

in the international system of units, the unit of torque is Newton meter. Note that it cannot be written as Joule. Joule is the unit of energy, Torque and energy are two different concepts.

in the calculation of torque, attention should be paid to the vertical distance from the axis of rotation to the line of action of the force in the plane perpendicular to the axis of rotation

6. When considering the balance of supporting force, gravity and friction, the object is regarded as a particle model, and the shape of the object is ignored. At this time, the object is regarded as a rotatable object, so the torque should be considered. In fact, it can be simply understood as the lever principle of junior high school.

7. Your problem is to regard the top as a fulcrum; X0d is m = 0 * 150 = 0; X0d is not! The bottom section is the fulcrum. What's the torque to the top! Answer: 92; The bottom section of x0d is the fulcrum, and the most underground load is 150kg, that is to say, the load on the fulcrum is 150kg & # 92; There is no force at the top of x0d! M = 0 * 2.4 = 0 or 0; X0d picture is like this, Safety Supervision Bureau, let's calculate the moment of the highest point! Answer: 92; The lower right point of x0d is the fulcrum, and the distance from the weight box to the fulcrum is 0.15 + 0.5m & # 92; X0d according to the moment balance # 92; The moment at the highest point of x0d is 50 * (0.15 + 0.5) = 32.5

8. "With A.B axis perpendicular to B.C axis = 400, rotate with A.B axis" is not clearly stated. What does it mean?

9. Torque: the proct of the force and the arm of force is called the torque of the force on the axis of rotation
that is: M = f * l
where m is the moment of force F on the rotation axis O. any moment that causes the object to rotate in anti clockwise direction is defined as positive moment, otherwise it is negative moment
unit: in the international system of units, the unit of moment is Newton * meter, abbreviated as Newton * meter, and the symbol is n * M.

10.

1. The meaning is not the same

the moment of force is the physical quantity of the rotation effect of the force on the object

force is the action of an object on an object

2. Different units

unit of moment: n · m

unit of force: n

< H2 > extended data:

force is one of the basic concepts in mechanics and the external cause of acceleration or deformation of an object. In dynamics, it is equal to the proct of the mass and acceleration of the object

When the concept of force forms a simple history push-pull object, we can intuitively realize the fuzzy concept of force. The action of force is reflected in the movement of the pushed and pulled object and the graal slowing down of the sliding object e to friction and finally stopping. The ancient Chinese Literature "Mojing" summed up this concept as "force, where form comes from, striving also"

That is to say, force is the reason that makes the object move vigorously. Therefore, force is naturally reflected in human consciousness. However, people have experienced a long struggle from the intuitive awareness of the concept of "force" to the strict scientific definition of "force"

In the west, before the concept of force was put forward in physical science. First of all, there is a debate in philosophy. Thales and others of the cosmological School of guchia thought that nature is living, and like the human body, it is a living tissue moving by itself. Under the guidance of this philosophy, there is no proposition of the origin of motion, and there is no concept of "force"

Later parmnides put forward the view that motion does not exist from logical reasoning. His opponents put forward that the source of movement is "force" to prove the existence of movement. This means admitting the original causal view that "force is cause and motion is result"

Plato's concept of force is basically immaterial. He thinks that the reason why nature endows the nature of movement is because there is an immortal living spirit. The last source of all forces in nature is the hidden soul of the world, which is the root of all physical activities. Of course, this metaphysical view is difficult to explain the kind of motion proced by gravity