A junior high school physics problem sinking and floating .

The more mass of the liquid spilled, the larger the G row and the greater the buoyancy!

In a cup it may be floating.

Buoyancy is equal to its own gravity m row B = m ball = 50g float so p b "p ball".

In cup A, m row, so p A is smaller than p B.

Because the volume of liquid overflowing from the two cups of A and B is the same, both are equal to the volume of the ball, and the mass of A is small, then the density of A must be less than B. As for the quality, I can't figure it out, is there anything to add?

The mass of the ball is 50g" is not clear, and there are some problems with the original title.

The scale indicator is container mass + water quality + wood block mass!!

If it is the mass of the container + the quality of the water + the mass of the wood block - the buoyancy of the wood block is subtracted by the upward buoyancy of the wood block, then in turn it is caused by the action and reaction force, and the wood block has downward pressure on the water, why don't you add it?

In fact, the simplest thing is to treat all three on the left as a whole, and it is obvious that what is weighed is the sum of the masses of the three.

Answer: The number of the scale is the mass of the container + the quality of the water + the mass of the block, do not consider the buoyancy.

Analysis:1The buoyant force applied to the block is water, and the reaction force is the pressure of the block on the water. This is the case for the interaction force, for the bench scale (or tabletop).Internal forces in the system, don't think about it.

2.For example, if two bricks are stacked on top of each other and placed on a horizontal tabletop, the pressure on the table is equal to the total weight of the two bricks. As for the bricks below, don't think about the bricks above.

3.Regardless of whether the blocks are floating, suspended, or sinking to the bottom in the container's water, the container's pressure on the horizontal table is equal to their total weight!

Hope you understand.

1.Because the mass is the same, the mass ratio is 1:1, and because the density ratio is 5:3, the volume ratio is inversely proportional to the density ratio according to v=m, so the volume ratio is 3:5

2.According to the floating and sinking conditions of the object, when floating and levitating, the buoyancy of the object is equal to the gravity, and the mass of the matter is the same as that of A and B, the gravity is the same, but they are subject to a buoyancy ratio of 4:5, so it is impossible to float or suspend at the same time, let the volume of A be 3x, B is 5x, F float A = 3x times 10 to the fourth power, B is multiplied by 10 to the fourth power, it can be seen that the buoyancy ratio is 2:

3, so these two objects must have a sinking bottom, because A's buoyancy is less than B's buoyancy, so only A must sink to the bottom, B can only float, according to the proportional calculation, B's buoyancy is multiplied by 10 to the fourth power, because floating, so B's buoyancy = B's gravity = A's gravity, A's gravity is multiplied by 10 to the fourth power, and the mass is multiplied by 10 to the third power, divided by the volume 3x, and the density is three.

Can you see it clearly, it seems that the conditions are a little insufficient, it should be said that the two small balls A and B are all submerged.

1: The ratio of mass equal density is 5:3, and the ratio of volume is definitely 3:5

2: The mass gravity of the two objects is the same, but the buoyancy is different, and the two states must be different, so A sinks with small buoyancy, and B floats or levitates (here floating).

A: Buoyancy : Gravity = 4 : 5 = Density of water : A. So the density of the A is.

The hollow part is half of the entire sphere.

If it is solid, then the mass is twice as large ( comparison density times volume = mass), and in the case of a hollow the buoyancy is equal to 1 4 gravity.

So when the mass is twice as much, the gravity is twice as much, and the buoyancy is the same, so you have to sink to the bottom and choose A

c, which can be pushed down step by step by the formula.

The answer is a, sink to the bottom. Because half the weight of a hollow ball is equal to the weight of 3 or 4 balls of volume water. Then the weight of the whole ball must be greater than the weight of the volume of water of the whole ball. Well, the ball will definitely sink to the bottom.

The external environment has changed, and so has the buoyancy of the water.

If the volume of the object is known, this problem can be solved. Otherwise, the conditions are insufficient and cannot be answered! Please check the original question carefully.

No picture, no truth!

Please upload**!

Before and after the apple is cut, the resultant force received is unchanged, let the buoyancy received by the small piece of apple be f1, the gravity force is g1, and the large piece is f2, g2

Before cutting, buoyancy = gravity, so after f1 + f2 = g1 + g2 after cutting, the small pieces of apples sink to the bottom of the water, so f1g2, so the large pieces of apples will float on the surface of the water. It is clear that only the less dense ones can float on the water, so:

It will (float up).

It should float up because the chunk has a nucleus inside it and there are voids in it.

Similarly, the density of apples is greater than that of water from the sinking of small pieces, so it sinks.

Sink like a small piece.。。 Because the density has not changed.

Sinking, the same substance has the same density, the apple is denser than water so it is suspended, if a substance is less dense than water then it will float and if the density is the same as the density of water it will be suspended. But objects can't come into contact with the bottom of the water, that's another story.

cBecause the volume of water discharged = the buoyancy to which he is subjected.

He receives a buoyancy of 90 with less than 100

So sink.

AC90G has a water volume of 90 cubic centimeters.

An object of 100g (1) has a volume of more than 100 cubic centimeters if the density is less than 1, and it will float on the surface of the water. It is possible to exclude 90 cubic centimeters of water (2) If the density is equal to 1, the volume of the object is equal to 100 cubic centimeters and will be suspended, and the volume of water discharged will be 100 cubic centimeters, so it will not be suspended (3) If the density is greater than 1, the volume of the object is less than 100 cubic centimeters and it will sink to the bottom of the basin, and 90 cubic centimeters of water may be excluded.

ⅱ。0 Newton.

Because these volumes of water are 10 Newtons, but submerged in water subjected to upward buoyancy is also 10N

So 0n