Grade 9 physics buoyancy questions, junior high school physics buoyancy questions

Not necessarily correct

It is correct to see if the ice containing a high density can rise to the surface, if the ice containing iron sinks into the water, and if there is a floating on the water, it is false.

It's not necessarily correct, but it's a pity that Hong Yan said the opposite.

See if the dense ice can come to the surface, and if the ice with iron sinks into the water, the water surface will not change after melting, because they can't melt, and they will discharge the same amount of water.

If it floats on water, the surface of the water drops. Because there is less water discharged after the iron sinks.

Correctly, regarding the latter point, whether he is sinking in the water or floating, the liquid level is down.

When the ice that sank in the water turns into water, the volume of the water obtained is less than the volume of the lost ice, and the liquid level drops.

And the liquid level that floats on the surface of the water drops after dissolving. You can think of ice as floating on the surface of the water, and if you hang an iron block on the ice, and the iron sinks into the water, the ice still floats on the water, but there is more volume into the water, and the liquid level is higher than if you just put the iron in the water. When the ice melts, the liquid level drops.

The volume of reduction is.

m molten iron density) - iron volume).

That's right!!! Ice dissolves in water!! The water surface does not change in height!! After melting water with ice containing iron blocks!! The water surface height increases!! This is because ice cubes containing iron have a higher overall density than ice cubes without iron cubes!!

1.The density is: 30 40 = kg m3

Analysis: It is stated that the mass of the truncated part is 30g, and the volume is 40cm3 copper density: kg m3

Mercury density: kg m3

g= m/s2

2.Solution: Let the volume of the copper block be v, then:

v=20/(

If the copper block is completely submerged, then buoyancy ===

20nBecause the buoyancy is greater than gravity, the copper block is not completely submerged, but partially submerged and floats in mercury by buoyancy and gravity 20n.

Since the resultant force is 0, the spring scale indicates 0.

Pressure = buoyancy Bottom area = 20 (100 10000) = 2000n m3

1) Matter * 40*10 (-6)m3=30*10 (-3)kg

2) Since the bottom surface of the rectangular copper block is parallel to the mercury plane (to be exact, the wording of this question is problematic), if the questioner wants to test whether the person's mindset has been broken, it should be said that the bottom surface is on the mercury plane, and there will be ambiguity according to the statement in the question. I guess the answer he asked us to calculate was very simple, the spring scale showed 0 and the pressure was 2000pa.

"The problem of immersion in volume" is indeed a difficult problem in buoyancy problems, taking the following problem as an example, it is possible to set a simple equation and solve it faster:

Example: If a 0 degree ice cube floats in 0 degree water, and the volume of its surface is 50 cm 2, what is the volume of the ice cube underwater?

The density of 0 degree ice is g cm3

Answer: The volume set underwater is v

then (v+50)*

v=450 i.e., the volume of the ice cube under water is 450 cm3

It can be used directly, but it is important to note that v refers to the volume of water discharged, that is, after you put something in, the page rises The area of the container (if the container is regular), and if there is liquid discharged from the container, the volume of water discharged must be added. (This should be a more comprehensive definition).

Only half of the float, simple, the drainage method measures the volume, you can calculate half of the mass, if you are only immersed in a fraction of the water, you use the fraction of the mass to calculate, I haven't done it, you can give it a try, it's better to take the completely immersed in the water first.

Find any relevant question from your assignment and complete it.

Do one, do one, do this every day (at least 10 days), do this question, and do it all the time.

After two questions, you will have a feeling.

Just remember that buoyancy = weight of the excluded liquid.

Junior high school physics is the use of several formulas back and forth, most of which are basic knowledge.

It's not much to do the questions.,Read it yourself.,If you don't understand or have doubts, ask your classmates (if you feel pressured to ask the teacher) to think more.,It's easy.。。。

As long as it is floating and levitating, buoyancy is equal to gravity.

Assuming that solid A is immersed in liquid B, the buoyancy f experienced by object A is equal to the gravitational force of liquid B from which it is displaced, which is also equal to the gravitational force of itself A.

Remember: buoyancy f = density of liquid g volume of object a in liquid = gravitational force of liquid b it dispels.

I think you will understand the rest, and you can ask questions again. Remember to adopt it.

I wish you progress in your studies and go to the next level! (

Hello landlord!

Topics of the buoyancy volume type.

Density of the object Density of water = volume immersed in water Volume of object Mass of object (including objects hanging on him) Volume of object Density of water = volume immersed in water Volume of object.

It is unchanged, which can be obtained from Archimedes' principle and the pressure of the liquid Although the density of ice is smaller than that of water, the excess part of the body is floating on the surface of the water, and of course the surface of the water does not change when it becomes water. Unchanged because buoyancy is equal to gravity.

The volume of water leaking out is the volume of that thing, and the buoyancy comes from the pressure difference between the top and bottom. With these two points it is understood.

It is important to calm down and read the question carefully to understand what is known and what is not known. Understand what is being asked for and use that formula.

That's how I learned, you have to believe in yourself.