Why is leverage vertical? Why are some levers horizontally balanced and some tilted balanced?

The principle of leverage is also known as the "leverage equilibrium condition". For a lever to be balanced, the magnitude of the two forces acting on the lever (the power point, the fulcrum, and the resistance point) is inversely proportional to their arms. Power Power Arm = Resistance Resistance Arm, expressed algebraically as f1 6 1 l1 = f2 6 1l2.

where f represents the power, L1 represents the power arm, F2 represents the resistance, and L2 represents the resistance arm. From the above formula, it can be seen that in order to balance the lever, the power arm is several times that of the resistance arm, and the power is a fraction of the resistance. When using a lever, in order to save effort, you should use a lever that is longer than the resistance arm; If you want to save distance, you should use a lever that is shorter than the resistance arm.

Therefore, the use of levers can save effort and distance. However, if you want to save effort, you must move more distance; If you want to move less distance, you have to work harder. It is impossible to achieve it with less effort and less distance.

It was from these axioms, on the basis of the theory of the "center of gravity", that Archimedes discovered the principle of the lever, that is, "when the double objects are in balance, their distance from the fulcrum is inversely proportional to their weight." The fulcrum of the lever does not have to be in the middle, and the system that satisfies the following three points is basically the lever: the fulcrum, the force point, and the force point.

The formula reads: the distance from the fulcrum to the force point (moment) * force = the distance from the fulcrum to the force application point (force arm) * force, so that it is a lever. There are also low-effort levers and labor-intensive levers, both of which have different functional performances.

For example, there is a pump that is stepped on by the foot, or a juicer that is pressed by hand, which is a labor-saving lever (arm > torque); But we have to press down a large distance, and there is only a small movement on the stressed end. There is also a laborious lever. For example, the crane on the side of the road, the hook for fishing things is at the tip of the whole rod, the tail end is the fulcrum, and the middle is the hydraulic press (torque > force arm), which is the laborious lever, but the laborious exchange is that as long as the middle force point moves a small distance, the hook at the tip will move a considerable distance.

Both levers are useful, but where they need to be used to evaluate whether they need to save effort or range of motion. There is also something called the axle, which can also be used as a lever, but the performance may sometimes be added to the calculation of rotation. The ancient Greek scientist Archimedes had such a famous saying that has been passed down through the ages:

If you give me a fulcrum, I can move the earth! "This sentence is not only an inspiring aphorism, but also has a strict scientific basis. Satisfied.

In a specific lever, the structure of its fulcrum is a structure that can make the lever self-stable.

What does that mean? That is, if there is an external force that generates a new moment, destroys the original equilibrium conditions, and makes the lever tilt, then in this tilting process, the self-stabilizing structure of the lever will produce a slight shift of the fulcrum, the redistribution of the weight of the arm arm, etc., so as to produce a moment that counteracts the external force, which is called the self-balancing moment.

The maximum self-balancing moment produced by the self-stabilizing structure at the maximum inclination is called the stability range of the lever.

For every 1 degree tilt of the lever, the self-balancing moment generated by the self-stabilizing structure is called the stability of the lever.

The reciprocal of stability is called the sensitivity of this lever.

For example, when the lever adds a small weight on the left side, the left moment increases, the lever tilts to the left, and the contact between the tapered fulcrum and the lever shifts slightly to the left (or because the fulcrum position is on the upper side of the horizontal rod, the center of gravity shifts to the right when it tilts left, which can be equivalent to the fulcrum to move left), the left arm decreases, the left moment decreases, the right arm increases, and the right moment increases, and the torque difference between the left and right sides is the self-balancing moment, which is opposite to the direction of the moment generated by the small weight.

As the tilt angle increases, the self-balancing moment increases, and when the self-balancing moment is equal to the moment generated by the small weight, the lever is stably balanced at this tilt angle.

If the small weight is too large and the torque generated is greater than the stable range of the lever, the lever will overturn and the lever structure will be destroyed, and the state cannot be calculated by the formula of lever balance.

Circular motion requires a force that changes direction, and this force that changes direction will only be vertical and perpendicular to the ground if the force is greater than the difference in inertia between the two objects. If the difference of inertia is equal to 0, the two objects (levers) will be horizontal. If the force generated by the difference in inertia is equal to and less than the force that changes direction, then the lever will reduce the force of change direction through different heights, that is, by tilting angle, so that it is in equilibrium with the force of poor inertia.

So some levers are tilted balanced.

Answer: As long as it is stationary, it is affected by the balance force. However, the levers used in the school experiments are regular wooden sticks with uniform texture and the fulcrum is at the position of its center of gravity, so it will be balanced in the horizontal position, and it is not in the horizontal plane to stand still, but it is not easy to find the force arm, because it is affected by gravity at this time, and the line of gravity must be perpendicular to the horizontal line, so the teacher will make it balance in the horizontal position.

As for what you are talking about about unbalanced forces and the like, any object that is moving in a straight line at rest or at a uniform speed must be subject to a balanced force, but the force we see is not the same, and the force arm is not equal, but the product of the two is equal. Therefore, it is balanced.

The lever can be balanced in any position.

To balance the lever, it is necessary to meet: power x power arm resistance x resistance arm, this condition.

If the leverage balance condition is met, the balance can be maintained.

The principle of leverage is that for a lever to be balanced, the two moments acting on the lever (the product of the force and the force arm) must be equal in magnitude. Namely:

Power Power Arm = Resistance Resistance arm, expressed algebraically as f1·l1=f2·l2. where F1 represents the power, L1 represents the power arm, F2 represents the resistance, and L2 represents the resistance arm.

As can be seen from the formula, whether the leverage is balanced or not only needs to satisfy the equality of the product, regardless of whether the lever is tilted or not.

The arm is the perpendicular line from the fulcrum to the line of action of the force.

As long as the support point is past the center of gravity, it can be balanced, regardless of the shape or density distribution of the item. So whether it is tilted or not, it does not affect the balance.

The condition of leverage balance is that the fs on both sides of the lever are equal, even if it is tilted, as long as the balance condition is met, it will be balanced.

When tilted, the force diagram is represented as the force applied to gravity and the force of the support point vertically upward, and the two forces are equal in magnitude and opposite in direction.

The principle of the bar is to adjust the balance effect, the level can achieve balance, and the tilt can also achieve balance.

Lever is an important concept in physics, which can convert the action of force into force with different directions, magnitudes and positions, which is widely used in daily 1110 and industrial production. But when the forces at both ends of the lever are unbalanced, the lever tilts or rotates, and then we need to understand why the lever tilts into balance.

In general, the equilibrium state of a lever is determined by the sum of the moments at both ends of the lever. Moment is the rotational effect of an object under the action of a force and is the product of the force and the arm of force. When the moments at both ends of the lever are equal, the lever reaches equilibrium.

However, when the moments at both ends of the lever are unbalanced, the lever tilts into balance. At this point, the equilibrium point can be found according to the definition of the moment and the lever can be balanced. The equilibrium point is when the axis of rotation of the lever is at **, and the lever will rotate or tilt around that axis to balance.

Another important factor that affects the balance of the lever is the magnitude and position of the force. If one end of the lever exerts more force than the other, the lever will tilt to one side. If the force applied to both ends of the lever is equivalent, but their positions are different, it will also cause the lever to tilt and balance.

In addition, the quality and shape of the lever also have an effect on its equilibrium. If the lever is not strong enough, or the shape is not suitable, its tilted equilibrium state will be affected.

In conclusion, the tilt equilibrium state of the lever is determined by a combination of factors. These factors need to be considered and controlled when formulating the design and using leverage to ensure the safety and stability of the leverage. <>

<> What is leverage?

In finance, leverage is the act of using a small amount of money to leverage excess profits, that is, to borrow money and use the borrowed funds for investment, and the result can amplify the effect of investment, which may be excess returns or huge losses.

The leverage ratio is the debt ratio.

Here's a simple example:

Last year, you invested 50,000 spare money in **, and the annual income reached 20%, and 50,000 became 60,000!

So you are full of confidence in yourself, and you plan to invest 1 million in **, and then borrow 950,000 from relatives and friends, with an annual interest of 10%, and repay 10,000 yuan with interest after 1 year.

Assuming that the market is still booming this year and the annual income is still 20%, then 1 million becomes 1.2 million, and after deducting the principal and interest, you still have 10,000 left, which means that you have taken 50,000 principal and got back 10,000. That's a lot of fun! Suppose you suddenly encounter a bear market this year and lose 20%, then 1 million becomes 800,000, and the principal with interest must be repaid at maturity.

So in this example, you use leverage, which allows you to earn more, but also lose more, which has a magnified investment effect.

Leverage is a double-edged knife, and the rational use of leverage can help accelerate the acquisition of wealth, which can allow investors to greatly increase their investment returns in the short term and realize their dream of getting rich overnight.

Increasing leverage can increase returns, but Huai Niansui will also increase risks. There are countless tragic cases of excessive leverage: in 2008, when the financial crisis struck, Wall Street investment banks were more than 30 times more leveraged, and three of the five largest Wall Street investment banks collapsed; In 2015, many people increased leverage, but as a result, they burst their positions, and some people had assets of more than 30 million yuan, and bought LeTV with leverage, but as a result, all their losses still owed more than 10 million to the company.

Warren Buffett, the god of stocks, has always opposed investors to increase leverage to buy**. For ordinary investors, they should avoid leverage and do not overestimate their ability to become rich in a hurry. High Oak borrowing money has two sides, and if it is used well, it is a help; If you don't use it well, it's destructive.

The general principle is to do what you can and to be moderately indebted, and over-borrowing almost always turns into a tragedy.