Objects that are light on the top and heavy on the bottom are relatively stable, that is, the lower the center of gravity, the more stable it is. When the tumbler is in equilibrium in an upright state, the distance between the center of gravity and the contact point is the smallest, that is, the center of gravity is the lowest. After deviating from the equilibrium position, the center of gravity always rises. So the balance of this state is a stable balance. Therefore, no matter how the tumbler swings, it will not fall. Another example is the experiment of "rolling on a cone" that we saw in the Science and Technology Museum. Because of the shape of the cone and the arc of the tracks on both sides, its center of gravity is falling, but it seems to be rising, and this rise is not in line with the facts in life. But this is just an illusion. Seeing its essence clearly, the center of gravity is lowered, so the lower the center of gravity, the more stable it is. In order to increase the stability of objects in life, we often increase the weight below, such as fan base, microphone bracket, bus stop sign and so on.

Why do some wine glasses fall off?

Objects that are light on the top and heavy on the bottom are relatively stable, that is, the lower the center of gravity, the more stable it is. When the tumbler is in equilibrium in an upright state, the distance between the center of gravity and the contact point is the smallest, that is, the center of gravity is the lowest. After deviating from the equilibrium position, the center of gravity always rises. So the balance of this state is a stable balance. Therefore, no matter how the tumbler swings, it will not fall. As for what you said will fall, there must be something wrong with the focus!

Why doesn't the tumbler fall?

It turns out that its center of gravity is relatively low. When you tilt it, there is a moment between its gravity and its landing point. Because at this moment, the tumbler will return to its original state, so the tumbler will keep swinging, but it will not fall. So the lower the center of gravity, the higher the accuracy.

Ladies and gentlemen, what does PK mean?

PK originated from online games.

PK: abbreviation of English player killing. On the surface, it means that players attack other players in multiplayer games. From the analysis of game mentality, it is to kill other players in any way without pre-agreed unfair competition.

Often I personally think it is inappropriate to use PK to describe super girl.

The reason why a tumbler can't fail.

Objects that are light on the top and heavy on the bottom are relatively stable, that is, the lower the center of gravity, the more stable it is. When the tumbler is in equilibrium in an upright state, the distance between the center of gravity and the contact point is the smallest, that is, the center of gravity is the lowest. After deviating from the equilibrium position, the center of gravity always rises. So the balance of this state is a stable balance. Therefore, no matter how the tumbler swings, it will not fall. Another example is the experiment of "rolling on a cone" that we saw in the Science and Technology Museum. Because of the shape of the cone and the shape of the tracks on both sides, its center of gravity is falling, but it seems to be rising, which does not conform to the facts in life. But this is just an illusion. Seeing its essence clearly, the center of gravity is lowered, so the lower the center of gravity, the more stable it is. In order to increase the stability of objects in life, we often increase the weight below, such as fan base, microphone bracket, bus stop sign and so on. Using this feature, we can do many interesting experiments and explain some phenomena. If you can become a beetle, open a capsule and put it in a small ball, you can turn your head back and forth. We often put a box on the table a little, but it won't fall. This is because the box is close to one end of the table, which is the "center of gravity", so the box hangs but will not fall. Acrobats who walk a tightrope also hold the balance bar to lower their center of gravity and achieve balance. Self-made method of tumbler: choose the packing box of spherical plastic Chinese medicine pills, which can be opened from the middle, just two hemispheres. Put a proper amount of plasticine or wet plasticine in one hemisphere to become the bottom of the tumbler, and stick a conical hat outside the other hemisphere to become the top of the tumbler. After the two hemispheres are buckled, draw a face and it is ready.

Why is a tumbler called a tumbler?

Because I want to be a tumbler ... no matter what setbacks I encounter, I don't want to go on ... The society has given us a lot of pressure ... whether it's family, friendship, career or trivial things in life ... sometimes I'm confused, disappointed and indispensable to life ... I just hope. Erect ... smile ... I hope we can all become stronger ... and face our future bravely ... so no matter how confused you are ... remember someone gave you a "tumbler". ...

The tumbler principle? Why doesn't the tumbler fall?

Tumbler is a toy with a long history, especially loved by children of all ages. Song Wei, a scholar in the Qing Dynasty, wrote in "One is the beginning of the era": "The tumbler began in the Tang Dynasty." According to the records, a long poem "Wine Beard" was presented to show the moral, and in the preface, it was said, "Hu Zhi's patrol, its rotation is also a talent." "This is the prototype of the tumbler. Then it gradually spread to this day and evolved into a toy to amuse children, adding endless fun to children and even adults. Then after studying theoretical mechanics, we can analyze the principle of "tumbler" from the perspective of mechanics and understand its related applications in daily life and production.

First, the principle of mechanics

The most common wine glasses are paper and mud bottom, that is, molded with paper pulp or glued with waste paper, and then made into a semicircular base with mud. After the two are bonded, put paper on the outside and color it. Others use wood as the bottom, and iron blocks and pebbles are fixed in the center of the bottom; There is also a "gourd" made by digging out the inner marrow with a small gourd and filling it with lead; There is a little tumbler made of eggshells and old table tennis balls today. All these wine glasses have a common feature: the upper body is a hollow shell, the lower body is a solid hemisphere, and the bottom is round. These characteristics make them have the same basic mechanical structure and can achieve the effect of "not falling down".

1. The main structure of the tumbler

A tumbler is a lightweight hollow shell; The lower body is a solid hemisphere, which is relatively heavy, and the center of gravity of the tumbler is in the hemisphere. There is a contact point between the lower hemisphere and the bearing surface. When the hemisphere rolls on the bearing surface, the position of the contact point will change. A tumbler will always stand on a supporting surface with contact points, and will always be a monopod.

2. Stability of tumbler balance

When the external force acts on the tumbler, it will lose its balance, but after the external force is removed, the tumbler can return to the balance state by itself, which shows that the tumbler has the ability to resist external interference and maintain balance, which is the stability of balance. The formation of this anti-interference and balance-keeping ability depends on the stress of the tumbler.

3. There are three kinds of forces on the tumbler.

First, the stress of tumbler balance. On the desktop, the tumbler is affected by two external forces: one is gravity G, the attraction of the earth to the tumbler; The other is the supporting force, the reaction force of the desktop to the bovine sphere. According to the equilibrium condition of an object, as long as the two forces are equal in magnitude and opposite in direction and act on a straight line, the tumbler can maintain a state of balance.

Second, the stress of tumbler tilt. When the tumbler leans, it is acted by two moments. We call the action of external force interference, and external force forms interference torque. The other is called resistance moment, which is formed by its own gravity. Originally, the tumbler was upright, but due to the action of external force, the external force produced a moment at the contact point between the tumbler and the finished surface, which made the tumbler tilt and broke the original balance. In addition, gravity does not produce moment, because the tumbler is upright, the line of action of gravity and the fulcrum are on the same line, and the moment is zero. Due to the external force, the tumbler leans, the hemisphere rolls to one side, and the contact point moves with it, forming a new contact point, that is, a new fulcrum. At this time, the line of action of gravity and the original fulcrum are not in a straight line, thus forming a moment, which is the resistance moment. It is precisely because of the formation and development of resistance moment that the interference of external force is resisted and prevented. The direction of resistance moment is just opposite to that of disturbance moment. At the same time, with the increase of the tilt angle of the tumbler, the offset of the center of gravity line of action is also increasing, and the magnitude of the resistance moment is also increasing. When the resistance moment is equal to the disturbance moment, the tumbler will enter a new equilibrium state-inclined equilibrium state, and the interference of external forces will stop. Therefore, after the tumbler is disturbed by external forces, the original balance is destroyed, but a new balance is formed, and the tumbler can keep the balance one after another. Although the ways of balance are different, the essence of balance remains unchanged, that is, dynamic balance.

Third, the pressure of tumbler recovery. From the perspective of potential energy, an object with low potential energy is relatively stable, and this object will definitely become a state with low potential energy. When the tumbler falls, most of the base with concentrated center of gravity rises, which leads to the increase of potential energy, so the tumbler should return to its original position. From the lever principle, when the tumbler falls, the point of action of the center of gravity is always at the end. No matter where the fulcrum is, although the arm of the base is short, the moment = force * arm of force, and the tumbler will still be forced by the end of the base. ......

Why does the "tumbler" never fail?

The first is the center of gravity. "Tumbler" attaches great importance to his heart, so he is more stable. But heavy objects like desk lamps sometimes fall down. The bottom of the tumbler is mostly spherical and rolls on the ground. Rolling friction is less than sliding friction, so it is easy for the tumbler to return to its original position after putting it down.