On the relationship between buoyancy and gravity of the object floating to float

Note: This is my eight grade writing a small paper, this review, in order to encourage their future HKU PhD research Road-Kujinganlai, tireless.

The reason for studying the relationship between buoyancy and gravity of the floating of an object is that the phenomenon I observe and draw from it is different from the knowledge described in the book. After my careful observation and analysis, I think the books on this aspect of knowledge has some shortcomings. Since we think there is a flaw, we should look for the right word.

It is well known that an object immersed in a liquid will rise as density is less than the density of the liquid until it floats on the liquid surface. The problem is that in this process, the relationship between the buoyancy of the object and the weight of the matter changes. People who have studied the "Buoyancy" section of physics know that buoyancy is constant in the process of floating, but greater than the weight of the material; when the liquid surface is exposed, the buoyancy gradually decreases until it floats to form a pair of equilibrium forces with gravity, i.e. F floating =g. As described above, you can see the answer to the second question of the 22nd question in the seventh chapter of Third Day physics, 06--07, Qixia Eight, in the next semester of the year. The question mark is: "Xiao Ming to tighten the lid of the small empty bottle into the water after a certain depth to let go, small empty bottle floating and eventually static in the process of water, how the size of buoyancy changes? "The correct answer to this question mark is:" Before the surface of the water, the buoyancy of the same size, beginning to reveal the water to the surface of the process, the buoyancy gradually smaller, and finally the buoyancy size and gravity equal. This shows that the buoyancy of the object during the ascent to the float is not less than that of gravity. Looking at the Internet and some of the relevant information, I find that knowledge about this is getting more consistent. But my views run counter to them.
Now I'm going to press a whole apple into the bottom of a bucket full of water and then let go and watch the apple move. It can be found that it floats quickly, and when it reaches the surface of the water no longer rises (I call this process "level up"), about half of its volume is exposed outside, but it is not floating at this time. Then the apples dipped into the water for a fraction. Then there was a small increase (the process was "level two rise") ... After several times, the Apple finally floats on the surface of the water, it can be found that at this moment the outside part is obviously less than in the first level rise to reach the maximum (or "first-class rise limit") in the outside part, or even less than the two-level rise ... So the volume of the liquid that is discharged when the object floats is larger than the volume that is discharged when the first-order rise limit is reached, i.e. the buoyancy of the object when it floats F float 'Buoyancy that is greater than the first-level rise limit F float '。 While floating, the g= F float ', so g> F float ', that is, when buoyancy is less than gravity when it floats, the buoyancy is not always reduced in the process of exposing the water to the surface.
Not only did Apple experiment so, I think that all the objects that can float in the liquid will produce this phenomenon, but some obvious, some not obvious. It can be seen that books and other relevant information on this aspect of knowledge did not give an appropriate practical statement.
What is the cause of this phenomenon? I think that in the floating process of the body by the action of buoyancy upward movement, so the object has a certain inertia, after exposing the liquid surface by inertia, buoyancy and gravity to the effect of the phenomenon of the number of liters down to a standstill on the liquid surface: In the process of ascending, by the role of inertia and buoyancy, The buoyancy of the object when it rises to its limit is less than the weight of the substance; at the first-level rise limit, because the buoyancy is less than the gravity, so the decline phenomenon, when the limit, and because the buoyancy is greater than the gravity, so the rise of the phenomenon ... Because of friction between the object and the liquid, the height of the ascent becomes smaller and higher, thus resting on the liquid surface.
So my final conclusion is that when the object floats to float, the buoyancy is less than the weight of the material, and the buoyancy is not always reduced in the process of exposing the liquid surface to the liquid surface. As long as we are good at observing subtle phenomena and thinking diligently, we will find something.

On the relationship between buoyancy and gravity of the object floating to float