Kneel down and ask experienced seniors for guidance on how to learn buoyancy

No matter what the mechanical problem, first of all, we must understand the analysis of force, the analysis of the general junior high force is always in a straight line, buoyancy is related to the volume of the object, in the search for the resultant force is not to forget the existence of gravity, let the straight line direction be the y direction, generally require the resultant force in the y direction, you first try to calculate the resultant force in the y direction to maintain a good position, and then to fully apply the conditions of the problem, buoyancy is related to what? This must be clear, related to the density of the liquid, related to the volume of the object, these two aspects are generally to know the density of the liquid and the volume of the object when doing the question, if the topic is not to find these two conditions by yourself, and then it is necessary to understand the condition of the three objects in the liquid, suspension, floating, sinking, which is related to the density of the object and the density of the liquid, and the relationship book is very clear. Basically, if you understand this, there is no problem.

The lever problem is a very simple law of proportionality, as long as the analysis of the relationship between the ratio of the force arm and the force is done correctly, you try to find a few more job diagrams, the analysis of the force arm of the diagram, and then the use of the law of proportionality should be no problem, more practice is the key, because there are many questions that are off topic, the analysis of the force arm is difficult to do for the first time, and the accumulation of analysis of the diagram is the key.

I don't know if you're satisfied with what I'm saying?

I just finished learning buoyancy, in fact, it's not difficult, isn't it f floating=g=mg=p liquid v row g Of course, you should also pay attention to the V row is the most difficult to find.

If it is completely and completely submerged, where, V row = v object, but it is also completely like this, for example, wood, only part of it is in the water, which V row = volume in the water, don't forget, also pay attention to the unit.

Of course, there is a test point that tells you that m, p will only find v row if you find v, that is, buoyancy.

I see? Oh, oh, remember, the density of water, the density of ice, the density of seawater!

Okay, that's all I said, do you feel like you're suddenly enlightened?

If you need it, I can give you some questions, practice more, and it will be fine!

Good luck with your exams! If the foundation is good, it is naturally not difficult!!

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Universal formula: F float = g = mg = p liquid v discharge g (Archimedes' formula) Concept: An object immersed in a liquid (or gas) is supported by a liquid (or gas) in a vertical upward direction.

Direction: Vertical up.

Cause: Buoyancy is created by the difference between the upward and downward pressure of a liquid (or gas) on an object.

Object Sinking and Floating Conditions:

F float g; Floating.

F float g; Levitation or floating.

Floating Archimedes Universal Formula:

f float = g = mg = p liquid v discharge g (Archimedes' formula) principle: an object immersed in a liquid is subjected to a vertical upward buoyant force.

The magnitude of the buoyancy is equal to the weight of the liquid it discards.

Calculation method: quadratic weighing method: f float = g-f1

Pressure difference method: f float = f up - f down.

Archimedes' principle: F float = g row.

Levitation or floating: F float = g matter.

Relationship between fluid and pressure:

Where the flow velocity is large, the pressure is small.

The pressure is strong where the flow rate is small.

That's it!!!

Sister, you remember, my brother gave me something absolutely necessary and absolutely useful, you have to study hard.

Brother is here to wish you the key points in the exam!!

Actually, you don't have to kneel and beg!! My brother will give it to you too!!

According to the formula, buoyancy focuses on the density of the object, its volume (the part immersed in the liquid), and the density of the liquid. The Dead Sea is not dead because the sea is dense and buoyant.

The buoyancy of an object submerged in the liquid is equal to the increased volume of the liquid (full is overflowing) * the density of the liquid.

The lever should find out the fulcrum, the force arm, and the direction of the force.

The principle of leverage is to save effort and effort. The force of the actual work should be perpendicular to the force arm; For diagonal pulling, the magnitude of the force in the vertical direction should be calculated first.

Where gravity does work, the distance between the center of gravity and the fulcrum is the force arm.

The longer the force arm, the less force is required to do the work, otherwise vice versa.

If you are really good at studying (the top 10 in the class), and the teacher is basically not about promoting good students, I still recommend that you go home to review, I am at home to review a few weeks before the high school entrance examination, do you know why it is good to study at home? You can relax at home, but you can be nervous at school. Each student is like a bow, and you have to release it when you take the exam, but can you guarantee that your bow will last until the exam?

Don't be too relaxed about studying at home. I stayed at home for a few weeks, and I ended up taking a city key exam.

Just go back two or three days before the exam, and don't forget to keep in touch with your teachers or classmates at school so you can always know about schedules and changes.

The most important thing is the basic knowledge, and you must be proficient.

Chinese is my biggest headache, and there's no good way to give it to you.

Mathematics and formulas should be memorized, and more intermediate and lower questions should be done to consolidate the foundation and have spare energy to do difficult problems.

Physics, it's the formulas, and the constants, so you have to keep them in mind.

Chemistry equations should be memorized, and the color properties of chemicals should also be memorized.

If the teacher's method is not suitable for you, don't pay too much attention to it Now there is still some time before the high school entrance examination You can use some more time to adjust Your mentality is very important during the exam Relax Hey, I wish you all the best in the high school entrance examination.

In fact, it is very simple, just understand the relationship between the density and volume of the object (the part immersed in the liquid), the density and weight of the liquid, etc.

My learning experience is that this kind of problem needs to be drawn more pictures, and many difficult problems can be understood at a glance as soon as they are drawn.

Of course, it's also a good idea to ask more questions about your teachers and classmates. As the saying goes: A conversation with you is better than ten years of study.

Buoyancy... As long as you grasp the volume of drained water = the volume of the object, it's good, grab this for each question, think about the density formula will do the problem... I'm pretty good at physics... Hehe.

Leverage... Just look at the vertical distance from the object to the fulcrum, which is the force arm. If you know the magnitude and direction of the force, won't you naturally introduce the moment formula... Right, no.

First of all, buoyancy is a very basic question in the high school entrance examination, so don't worry, if you are in a hurry, take the initiative to find your teacher to make up for you, he will not say you.

Check it out in my space. There are a lot of junior high school physics problems.

First of all, learn to judge the state! I choose a formula by a state!

Memorize the formula. Do more questions!

I'm also a high school student this year.

I am also depressed.

Memorize the formula, then do a few experiments and relate him to real life. Just build a physical model. Anything is easy to do.

Force analysis is also indispensable, and it will be much easier to find a balance.

That's what I learned, and it worked.

I, if you have any questions, just look for me.

Hehe, I didn't understand much at first. Then I bought that "Lesson Pass", there is an explanation, and I understand it at once, really, try to go down to the class. You can buy it at Xinhua Bookstore

Method 1: Archimedes' principle, f float g row.

Method 2: Two forces balance, for floating and suspended objects, F floating G object Method 3: Weighing method, F floating G object F pulling.

Method 4: Pressure difference method, f float f up f down, that is, the pressure difference between the upper and lower surfaces is buoyancy.

If you don't know, please ask.

Method 1: Archimedes' principle.

Method 2: Use two forces to balance.

Method 3: Weighing method.

Method 4: Pressure difference method.

Archimedes' principle. Or according to the two-force balance.

Buoyancy is the upward force experienced by an object in a liquid, which is related to the volume of the object immersed in the liquid, that is, the amount of buoyancy is related to the depth and volume of the object immersed in the liquid. Buoyancy has a wide range of applications, such as diving, boat design, architectural design, and more. But sometimes we need to increase the buoyancy of an object, so how do we increase the buoyancy of an object?

Here are a few ways to increase the buoyancy of an object:

Change the shape of the object.

The shape of the object determines the depth of immersion of the object in the liquid, which affects the buoyancy experienced by the object. Changing the shape of the object can make the depth at which the object is immersed in the liquid shallower, thereby increasing the buoyancy experienced by the object. For example, in diving, divers can use a wetsuit to change their shape, make their immersion shallower and increase their buoyancy.

2. Change the density of the object.

The density of the object is also an important factor affecting the magnitude of buoyancy. The less dense the object is, the more buoyant force is experienced, so the buoyancy of the object can be increased by changing the density of the object. For example, in diving, a diver can add gas to the wetsuit, making the wetsuit less dense and thus increasing its own buoyancy.

3. Increase the surface area of the object.

Increasing the surface area of an object increases the area where the object is in contact with the liquid, thereby increasing the buoyancy experienced by the object. For example, in diving, divers can use large harpoons to increase the surface area of the harpoons and increase the buoyancy to which the harpoons are subjected.

Fourth, add buoyant substances.

A buoyant substance can be added to the surface or inside of an object, so that the buoyancy experienced by the object increases. For example, in diving, the diver can add foam or gas to the wetsuit, which increases the diver's buoyancy.

In conclusion, there are many ways to increase the buoyancy of an object, and we should choose the appropriate method according to the specific situation to achieve our purpose. However, it should be noted that increasing buoyancy also brings some safety hazards, such as excessive buoyancy may cause objects to lose balance, so you need to pay attention to safety.

The essence of buoyancy is the difference in pressure between the upper and lower surfaces of an object immersed in a liquid. As long as you can calculate the difference between these two pressures, these two formulas can be easily derived.

First fully understand the actual meaning of buoyancy: for example, "Who has the greater buoyancy of a big stone or a small wood?" Don't take it for granted that because the wood can float, it should be considered by Archimedes' principle, and consider it with f buoyancy = liquid density * v invasion, and come to the correct conclusion that "the buoyancy of a large stone is greater than the buoyancy of a small wood", so that your buoyancy has been half learned; Then, it is necessary to know how to summarize the rules, such as:

The rise and fall of the liquid level of the ice-pack juice after it melts in the brine, the rise and fall of the liquid level after the ice-pack juice melts in the brine, the rise and fall of the liquid level after the ice-pack bubbles melt in the brine, etc. It is recommended to use the book "Question Bank for Top Students", which is quite well organized in this chapter. I can see that you are very motivated, come on!

Always grasp the theorem and listen carefully in class.

This chapter describes buoyancy, the conditions of the float and sink of objects, the Archimedes' principle, and the application of buoyancy To learn these knowledge, we should apply the knowledge of density, gravity, the balance of two forces, the synthesis of two forces on the same line, the pressure and pressure of liquids, etc., which have a strong comprehensiveness, so it is difficult to learn The key to learning this chapter well is to clarify the following misunderstandings, and correctly understand the concept of buoyancy, the conditions for the rise and sink of objects, and Archimedes' principle 1. Under what circumstances is an object subject to buoyancy, the common mistake is " Objects that float up are subject to buoyancy, and objects that sink are not subject to buoyancy" Is this really the case? So please do this experiment: if you lift an object that sinks in the water or an object that sinks to the bottom of the water out of the water, you will feel lighter when you lift it in the water than when it comes out of the water, because the object is buoyant in the water.

The pressure on the upper and lower surfaces of the object immersed in the liquid (gas) body is different, and the pressure on the lower surface is stronger than the pressure on the upper surface, so the upward pressure is always greater than the downward pressure, which is the reason for the buoyancy force, the magnitude of the buoyancy is equal to the pressure difference between the upper and lower surfaces of the object, and the direction is always vertical and upward Therefore, as long as the object immersed in the liquid or gas, whether it floats on the top or sinks to the bottom (except in the case where the bottom of the object is sealed with the bottom surface of the container), and whether it floats or sinks, Objects are subject to buoyancy 2. Common mistakes when using Archimedes' principles to solve problems. This article has 1 page in total).