On the rule of parallelogram The maximum tensile force a string can bear is g. now tie an object of gravity g to the middle point of the string, hold the two ends of the string respectively with two hands close, and then slowly separate left and right along the horizontal direction. When the string breaks, the included angle between the two sections of the string should be slightly greater than A．30° B．60° C．90° D.120° After reading the answer, I don't know why when both forces are g and their resultant force is g, the included angle is 120 degrees? It seems that a parallelogram with an internal angle of 120 degrees cannot be divided into two equilateral triangles?

On the rule of parallelogram The maximum tensile force a string can bear is g. now tie an object of gravity g to the middle point of the string, hold the two ends of the string respectively with two hands close, and then slowly separate left and right along the horizontal direction. When the string breaks, the included angle between the two sections of the string should be slightly greater than A．30° B．60° C．90° D.120° After reading the answer, I don't know why when both forces are g and their resultant force is g, the included angle is 120 degrees? It seems that a parallelogram with an internal angle of 120 degrees cannot be divided into two equilateral triangles?

Drawing,
The parallelogram is a diamond
When one angle of parallelogram = 120 degree
Then f 1 = f 2 = g (the diagonal of G = 120 ° is the resultant force)
So the angle between F1 and g = the angle between F2 and g = 60 degrees

How to check the comprehensive operation of decimal division

Division is checked by multiplication... The checking of comprehensive operation is the checking of reverse process

The vector follows the parallelogram rule. What is the parallelogram rule?

When two forces are combined, the line segment representing the two forces is used as the adjacent edge to make a parallelogram. The diagonal line between the two adjacent edges represents the magnitude and direction of the resultant force. This is called the parallelogram rule

Which number is the biggest
It is known that 12% of a is 13, 13% of B is 14, 14% of C is 15, and 15% of D is 16. Which number is the largest

It is known that 12% of a is 13, 13% of B is 14, 14% of C is 15, and 15% of D is 16. Which number is the largest
[solution]: A: 13 △ 12% = 108.3333
B: 14 △ 13% = 107.6923
C: 15 △ 14% = 107.1428
D: 16 △ 15% = 106.6666
A is the biggest!

How to prove the formula in the rule graph of parallelogram

As shown in the figure (1) & nbsp; F & # 178; = F1 & # 178; + F2 & # 178; - 2F1 * F2 * cos ∠ 1 = F1 & # 178; + F2 & # 178; - 2F1 * F2 * cos (180 ° - α) = F1 & # 178; + F2 & # 178; + 2F1 * F2 * cos α Ψ f = √ (F1 & # 178; + F2 & # 178; + 2F1 * F2 * cos α) & nbsp; (2) Tan θ = F2 * sin α / (F1 + F2 * cos α)

What is the parallelogram rule?
How to calculate vector and parallelogram rule? OK, I'll give integral

In a narrow sense, we should replace "force" with "vector"
When two vectors are combined, a parallelogram is made by taking the directed line segment representing the two vectors as the adjacent edge. The diagonal between the two adjacent edges represents the size and direction of the sum of the two vectors. This is called the parallelogram rule

How to prove the physical parallelogram rule?
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If you have studied vector, you can use vector. You can also see from the coordinate axis that the coordinates of the diagonal of a parallelogram are equal to the sum of the two sides, or you can decompose all the components of the resultant force into a cross, and the sum of each direction is zero

The parallelogram rule question asks the master to answer
In the parallelogram rule, the effect of two components of force is equal to the effect of resultant force (it is proved by the rubber band experiment that the rubber band is not regarded as a particle). But why should the general object be considered as a particle? If a piece of wood is placed on the horizontal table, the resultant force of 1000N is 0, and the resultant force does not make the object deform The effect of force includes deformation and motion state. Other vectors such as displacement, such as 100m to the East and 100m to the west, do not need to regard the object as a particle
What's more, how can the experiment of rubber band be extended to general use?
The rubber band is pulled by two ropes
It seems to be separated
It seems that the two points have nothing in common
The experiment to prove the parallelogram theorem
It's a rubber band, two ropes pull in two directions
There's nothing in common --

1. The common point force refers to the force or the opposite extension of the force to a point, which is called the common point force. So the two forces of pulling the rubber rope are the common point force
2. When we study the effect of resultant force and component force, we generally study the effect of force on the change of object motion state, not the effect on deformation
3. Under the action of common point force, the object will not rotate. If the forces are not common point, there will be rotation, so the combination of force can no longer be used, but the lever principle will be used

Proof process of parallelogram rule
The teacher came to this conclusion after doing the experiment, but I want to know how to prove it in theory. The knowledge should be as simple as possible. I'm a freshman in senior high school. If I haven't learned some physical quantities used in the proof, please attach the definition (of course, it's best to prove it)

This also needs to be proved? The whole experimental process is very clear, no matter from the experimental process or the experimental thought, there is no problem. For details, please refer to Baidu Encyclopedia! Learning can't be too serious. It's also very important to learn the methods and ideas in the experiment. In this way, you can make your thinking more open when you encounter strange problems!
You have to prove it in theory. You'd better forget it when you're a freshman in high school. After you learn vector in high school, you'll understand!

In the experiment of verifying parallelogram rule
In addition to the supply of other necessary equipment, only one spring scale will be provided. Can this experiment be completed? How to operate?

all the steps as like as two peas, only when two springs are used, the original step is divided into two steps, and one of the springs is replaced by a rope (which is also made by the experimental instrument). That is all. Two.