In physics, the formula of lever balance is f1l1 = f2l2, so what kind of physical quantity can f1l1 be expressed

In physics, the formula of lever balance is f1l1 = f2l2, so what kind of physical quantity can f1l1 be expressed

Torque: the cross product (m) of position vector (L) and force (f). In physics, it refers to the force that makes an object rotate multiplied by the distance to the rotation axis
M = l × F, where l is the vector from the axis of rotation to the point of force, f is the vector force, and the moment is also the vector force
The dimension of moment is distance x force, which is the same as that of energy. However, the moment is usually expressed in Newton meters instead of joules. The unit of moment is determined by the unit of force and arm of force
moment of force
Moment (m), in n · M
How to calculate (4x + 20) / 4 = (6x-20) / 5 (4x + 20) / 4-2 = (6x-20) / 5 (4x + 20) / 4 + 2 = (6x-20) / 5
(4X+20)/4=(6X-20)/5
5(4x+20)=4(6x-20)
20x+100=24x-80
-4x=-180
x=45
(4X+20)/4-2=(6X-20)/5
5(4x+20)-40=4(6x-20)
20x+100-40=24x-80
-4x=-140
x=35
(4X+20)/4+2=(6X-20)/5
5(4x+20)+40=4(6x-20)
20x+100+40=24x-80
-4x=-220
x=55
To solve the equation 1.14x-16 = 3x + 6 2.6x (x-45) = 3x-120
14x－16＝3x+6
14x-3x=16+6
11x=22
X=2
6×（x-45）＝3x-120
6x-270=3x-120
6x-3x=270+120
3x=390
x=130
Please take it. Thank you
Given that the intersection point of parabola y = x ^ 2 + 2mx + m-2 and Y is above the x-axis, then the intersection point of quadratic function y = 1 / 4x ^ 2 + (M + 1) x + 5 and x-axis is?
The intersection of parabola y = x ^ 2 + 2mx + m-2 and Y is above the x-axis, which indicates that the intercept of y-axis is positive
Therefore, M > 0-2
y=1/4x^2+(m+1)x+5
Discriminant = (M + 1) ^ 2-4 * 1 / 4 * 5 = m ^ 2 + 2m + 1-5 = m ^ 2 + 2m-4
Because m > 2, m ^ 2 + 2m-4 > 4
So there are two different intersections between function and x-axis
If the solution of the binary linear simultaneous equation 2x − 3Y6 = 415x + 15y − 53 = 0 is x = a, y = B, then A-B = ()
A. 53B. 95C. 293D. −1393
Firstly, by simplifying the equations, we get 2x − 3Y = 24, ① 3x + 3Y − 1 = 0, ② ① + ②, we get 5x = 25, that is, x = 5. Y = - 143. ∵ x = a, y = B, ∵ A-B = X-Y = 5 - (- 143) = 293
Leverage balance formula how to express specific (the best example) thank you
How to know the balance condition of leverage
Is it just the arm of force and the force
First of all, understand the formula f1l1 = f2l2, where F1 and F2 represent different forces respectively, and L1 and L2 are power arm and resistance arm. To keep the lever balanced, the key is that the length of power arm and power value are equal to the length of resistance arm and resistance force. First, take a simple example, look at this balance, with two weights hanging on the left side, then f
F1L1=F2L2
F1S1=F2S2
S1 and S2 are the distance from the action point to the fulcrum of F1 and F2
F1 and F2 are in the same direction, F3 is in the other direction
Then F1 * L1 + F2 * L2 = F3 * L3
The content is: f1l1 = f2l2. (expressed by formula) Chinese athletes Meng GuanLiang and Yang Wenjun won the 500m double canoe championship in Athens Olympic Games. According to the lever classification, the oars of rowing belong to the hard lever
According to the condition of lever balance, that is, power multiplied by power arm is equal to resistance multiplied by resistance arm; according to the relationship between power arm and resistance arm, lever is classified, that is, power arm greater than resistance arm is labor-saving lever, power arm less than resistance arm is laborious lever, power arm equal to resistance arm is equal arm lever. The condition of lever balance is that power multiplied by power arm is equal to resistance multiplied by resistance arm With the resistance arm, unfold the alphabet
The content is: f1l1 = f2l2. (expressed by formula) Chinese athletes Meng GuanLiang and Yang Wenjun won the 500m double canoe championship in Athens Olympic Games. According to the lever classification, the oars of rowing belong to the hard lever
According to the condition of lever balance, that is, power multiplied by power arm is equal to resistance multiplied by resistance arm; according to the relationship between power arm and resistance arm, lever is classified, that is, power arm greater than resistance arm is labor-saving lever, power arm less than resistance arm is laborious lever, power arm equal to resistance arm is equal arm lever. The condition of lever balance is that power multiplied by power arm is equal to resistance multiplied by resistance arm The resistance arm is represented by letters, that is, f1l1 = f2l2;
The power arm of the Olympic canoe is smaller than the resistance arm
The answer is: the resistance of the lever arm multiplied by the resistance of the lever arm
The length of both sides of the lever is L1 and L2 respectively, the weight is M1 and M2 respectively, the angle is I, and the moment action f = ml is L1 * M1 * Sini and L2 * M2 * Sini respectively
The torque difference is (L1 * m1-l2 * m2) * Sini. When I is 0, the torque difference is 0, reaching equilibrium; otherwise, if the torque is not equal, it is unbalanced
Lever is the application of moment action and the relationship between force arm and force: the condition of lever balance is that the power multiplied by the force arm equals the resistance multiplied by the resistance arm, and the force arm is f1l1 = f2l2 at the time of balance
The length of both sides of the lever is L1 and L2 respectively, the weight is M1 and M2 respectively, the angle is I, and the moment action f = ml is L1 * M1 * Sini and L2 * M2 * Sini respectively
The torque difference is (L1 * m1-l2 * m2) * Sini. When I is 0, the torque difference is 0, reaching equilibrium; otherwise, if the torque is not equal, it is unbalanced
Lever is the application of moment action and the relationship between force arm and force: the condition of lever balance is that the power multiplied by the force arm equals the resistance multiplied by the resistance arm, and the force arm is f1l1 = f2l2 at the time of balance
F1L1=F2L2
The arm of force is the vertical distance from the equilibrium point to the direction of the force
As long as we know the force and arm of force, we can know whether the lever is balanced
F1 * S1 = F2 * S2 in the actual situation, the self weight of the lever should also be considered
The lever balance condition is based on the experiment, the formula is: L1 * F1 = L2 * F2, only need to consider the force and arm of force, the gravity of the lever is basically ignored, the questioner will generally say that this is a light lever (that is, the gravity is ignored), if you have to bring a lever, the gravity formula is: L1 * (G1 + G2) = L2 * (G3 + G4)
Examples can be found on the Internet, you can also buy exercises, not to mention here. Let's see how hard I try to score! I lack points! ... unfold
The lever balance condition is based on the experiment, the formula is: L1 * F1 = L2 * F2, only need to consider the force and arm of force, the gravity of the lever is basically ignored, the questioner will generally say that this is a light lever (that is, the gravity is ignored), if you have to bring a lever, the gravity formula is: L1 * (G1 + G2) = L2 * (G3 + G4)
Examples can be found on the Internet, you can also buy exercises, not to mention here. Let's see how hard I try to score! I lack points! Put it away
Lever balance is actually the balance of the rotation of the object, which corresponds to the balance of the force corresponding to the translation of the object. The physical quantity of lever balance is called moment (m), which is the product of the magnitude of the force and the distance from the action line of the force to the fulcrum, that is, force x arm of force, in n · m, and can not be written as the unit Joule (J) of energy. As shown in the figure, the fulcrum of the lever is at O, which is 1 / 4 of the length from the left end. There are F1 and F4 actions at the left and right ends respectively. There is F2 action in the middle of the whole lever, and there is F3 action at 3 / 5 from the left end. The angle between the lever and the horizontal bar is 30 degrees. According to the definition of moment, the moment of F1 relative to the fulcrum O is M1 = F1 × L / 4 = 0.25f1lf2 relative to the fulcrum O is M2 = F2 × L / 4 = 0.25f2lf4 relative to the fulcrum O is M4 = F4 × 3L / 4 = 0.75f4lf3 is an inclined force. According to the definition of moment, the arm of force is the distance from the point O to the action line of force. You can extend F3 and then make the vertical section from O to the extension line. The length of the vertical section is the force of F3 Arm. The second method is to decompose F3 into two vertical orthogonal separated F3X and F3Y. The extension line of F3Y whose arm of force is 3L / 5-l / 4 = 0.35lf3x crosses the fulcrum O, so if the arm of force is zero, then the moment of F3X is zero, then the moment of F3 m3 is only F3Y moment. Therefore, when m3 = F3Y × 0.35L = 0.5f3 × 0.35L = 0.175f3l lever is balanced, the algebraic sum of all moments is zero. That is & nbsp; & nbsp; & nbsp; Positive torque + negative torque = 0 torque has direction, which is divided into clockwise and counterclockwise directions. In the figure, we can see that if only F1 acts, the rod will rotate counterclockwise around point O. we can define that the torque in counterclockwise direction is positive, then M1 of F1 is positive torque, and F2 acts alone to make the rod rotate clockwise, so M2 is negative, which is substituted into the above When you balance the equation, you add a minus sign. According to the relationship in the graph, we can have (M1 + M4) + (M2 + m3) = 0, that is & nbsp; & nbsp; & nbsp; (0.25f1l + 0.75f4l) + (- 0.25f2l-0.175f3l) = 0
f1*l1=f2*l2
Request equation 4x + 18 = 6x-8
4x+18=6x-8
18+8=6x-4x
26=2x
x=13
Transference
18+8=6X-4X
26=2X
X=26÷2
X=13
6x-4x=18+8
2x=26;
x=13
The solution equation: 1, 2 (x-4) = 3 (X-12) 2, 7 (3-3x) = 14x + 3.5
1. Solution: 2x-8 = 3x-36
36-8=3x-2x
x=28
2. Solution: 21-21x = 14x + 3.5
21-3.5=14x+21x
35x=17.5
x=0.5
The axis of symmetry of the parabola y = (M2-2) x2 + 2mx + 1 with downward opening passes through the point (- 1,3), and the value of M is obtained
∵ the symmetric axis of the parabola y = (M2-2) x2 + 2mx + 1 with downward opening passes through the point (- 1,3), ∵ - 2M2 (M2-2) = - 1, M2-2 < 0, and the solution is: M1 = - 1, M2 = 2 (not suitable for the problem), and∵ M = - 1
If the solution of binary linear equations {2x-3y = 4, 15x + 15y-5 = 0 is x = a, y = B, then a-b=
A 5 / 3 B 29 / 3 d-139 / 3
x=6,y=-2/3,a-b=x-y=20/3