# buoyancy's questions - English 1answer

371 buoyancy questions.

### Buoyancy Force and Added Mass

0 answers, 13 views acceleration buoyancy
If I consider a spherical particle immersed in a fluid, the force balance gives that it is affected by buoyancy and stoke drag. When I instead consider a spherical particle immersed in a fluid, ...

### -1 Does a Helix shaped object floating in water stream rotate?

1 answers, 60 views torque buoyancy
A Helix shaped light weight object is placed a water stream. Does it rotate? It is pushed by water body, will it also experience turning force and thus rotate?

### How buoyancy and convection are related?

1 answers, 35 views buoyancy convection
If I'm not wrong buoyancy formula is $$F_{B}=\rho gv_{sub}$$ In convection it is said that fluids with less density come up and parts with lower density ,which are cooler , go down and this cycle ...

### 2 Why oxygen bubbles are larger than hydrogen bubbles during water electrolysis?

During water electrolysis, I found the oxygen bubbles are usually larger than the hydrogen bubbles. I think the reason is because different gases have different contact angles. The contact angle of ...

### 1 Point of application when the force is the up thrust?

We have been taught that the point of application is the point at which the force is applied. In contact forces, the point of application is the point of contact and in forces acting from a distance, ...

### 1 Is it possible to make a vacuum balloon filled with electromagnetic radiation float?

Given the right materials and structure, could you theoretically use radiation pressure to keep a equilibrium amount of pressure inside a special vacuum balloon so that it would float. (ignoring the ...

### -1 Determine velocity of balloon from known Buoyancy, mass and surface [closed]

I need to know how to get velocity of weather balloon, if I know it's buoyancy force, mass and surface(diameter). I am using now $$v = 0.5t\left(\frac{F_\text{all}}{m}\right),$$ [$m$ = mass, $v$ = ...

### -6 If I jump from space using a spacesuit filled with hydrogen could I survive the fall? [closed]

If I fill a spacesuit to its maximum volume with hydrogen while wearing it (who cares about the breathing part anyway) and jump from space (let's say, from 100km above sea level, a.k.a. Karman Line), ...

I took an empty clear sphere with radius r, put some weight inside this sphere, and put in into the water. I calculate the buoyancy force as: Volume of the sphere = Volume of the water displaced ($V_{... ### 3 Why can't hot air balloons fly higher then helium balloons? I have read these questions: Hot air balloon trajectory predictions Do atmospheric physics prevent hot air balloons from ascending over 60,000ft? What is precisely the reason that a helium balloon ... ### Are these sandals floating due to surface tension or buoyancy? 1 answers, 40 views surface-tension buoyancy Having an argument. If the sandals are wet (which I think we can assume they are), then they have broken the surface, correct? And if they’ve broken the surface, then that leaves only buoyancy to hold ... ### 5 Why does not a bubble in a thick hand sanitiser not rise? Here is a picture of a bubble trapped inside a thick hand sanitiser. These bubbles never rise despite not sticking to the walls! They just remain stationary, in the middle of the liquid, despite the ... ### 40 Can ants walk on liquid mercury? [closed] I'm not a physicist, but I was wondering: Can ants walk on dense liquid like mercury and why? ### 49 Why does ice melting not change the water level in a container? 8 answers, 83.175 views water buoyancy states-of-matter ice I have read the explanation for this in several textbooks, but I am struggling to understand it via Archimedes' principle. If someone can clarify with a diagram or something so I can understand or a ... ### 1 Wood vs static Water 0 answers, 37 views water density buoyancy fluid-statics First of all: I'am not a physicist or anything close to it. I jhust enjoy to think about certain thinks in a different way and to ask for a much more detailed "how". So here is what keeps me from ... ### 1 Confusion on center of movement while tilting a floating body 0 answers, 29 views classical-mechanics buoyancy When a floating body is tilted at an angle$\theta$, the restoring moment will be about the metacenter. But is the tilting movement about the center of gravity? If it is, then it looks like there ... ### 2 How much electricity does it take to create hydrogen from water depending on the water's pressure? Imagine creating bubbles of hydrogen and oxygen underwater at a particular depth using electricity. Then reusing the energy of the bubbles going upward to the surface ( buoyancy ). How is the energy ... ### How is the swimmer's buoyancy rate figured out in plain terms 0 answers, 15 views buoyancy I wish I could explain swimmers how can they figure out their buoyancy rate in such a way that they can do something about it. ### 1 Work done in lifting a object from underwater if it displaces$W'$of water? [closed] A spherical shot of W gm weight and radius r cm, lies at the bottom of cylindrical bucket of radius R cm. The bucket is filled with water up to a depth of$h\,\mathrm{cm}\left(h > 2r\right).$... ### 3 Why is it easier to float when the body is relaxed? Anyone who swims or learns how to swim must have experienced this simple observation. When the muscles in our bodies are relaxed, we tend to float; whereas stiffness/tensed body tend to drown. So ... ### 3 Balloons and lifting gases 4 answers, 6.136 views forces pressure buoyancy faq Hydrogen is the lightest element, so it's cable of lifting the most weight in out atmosphere (probably not the best terminology there, but you get the picture) Would hot hydrogen (in the same sense ... ### “If an object was dropped into water from two different heights, so that it doesn't hit the bottom, would the terminal velocity be different?” If an object was dropped into water from two different heights, assuming that it doesn't hit the bottom, would the terminal velocity be different?". Suppose that container has a lot of depth that it ... ### -3 When does wet cloth weigh less than dry [closed] 2 answers, 82 views mass buoyancy weight What liquid should you use to wet a piece of cloth, so that weight of a wet cloth is less than weight of a dry cloth? The only idea I have is that you should wet the cloth in sunflower oil and then ... ### Buoyant Force and the Weight under water 3 answers, 563 views buoyancy The source of my question can be found via this link: https://www.youtube.com/watch?v=wwjtuZ5vTvc&index=94&list=PLAD5B880806EBE0A4 There is an object that weight 10N outside of water and 2N ... ### 1 Is the buoyant force decreasing in upper layer the deeper water? 2 answers, 67 views forces buoyancy I'm asking about a real experiment. As in this I have read in an answer in this site which is What atomic forces are acting to resist me pushing an air filled bottle underwater?. As in ben51's answer ... ### 2 Submerge an upside down bottle into a ball of water in space 2 answers, 73 views gravity pressure buoyancy fluid-statics On earth if you submerge an upside down bottle into a pool or some large tub of water the bottle doesn't fill with water. I believe this is because of air pressure and air has nowhere to go. What ... ### 5 What atomic forces are acting to resist me pushing an air filled bottle underwater? Yes air is less dense than water but how does the bottle know to rise or indeed to move? It's not electromagnetism I think. Does this have a relation to gravitational forces? Is it to do with the ... ### 1 Why don't solids fall in air? One can do a neat little experiment as described here and discover that atmospheric pressure is sufficiently strong to keep water up against its own hydrostatic pressure as long as there is a material ... ### 2 how dense fluid affect the buoyancy force? 5 answers, 41.202 views buoyancy I read a story regarding the Archimedes' principle in a magazine of popular science and I am thinking of the following question: how does the density of the fluid change the buoyancy force for the ... ### 1 Why do objects float in liquids denser than themselves? [duplicate] Why do objects float in liquids denser than themselves? I know that a balloon floats on water because it has air in it, but why? ### buoyancy of compressed air as discussed in a previous thread [closed] 2 answers, 52 views air buoyancy i was reading a previously locked thread about the compressed air from tires in the movie transporter three, and the writer asked if compressed air is heavier than regular and therefore does not float.... ### 1 Where does the buoyant force come from? If I place a cube in water, the force at the top of the cube, F1 will be Ahρwg. Where, A = cross-sectional area h = height at the top ρw = density of water g = acceleration due to gravity All this ... ### Would a perfect cube of lesser density float if placed perfectly on the surface of a liquid container? 0 answers, 36 views buoyancy If a cube -"of lesser density than the liquid"- with perfectly flat surfaces was placed in a liquid container with a perfectly flat bottom , so that there were no liquid molecules between the two ... ### 13 What is the oscillation frequency of a buoyant cylinder? 2 answers, 441 views fluid-dynamics oscillators buoyancy Suppose a cylinder sits upright in "dry water" (zero viscosity). The cylinder has half the density of the water, and we'll ignore the dynamics of the atmosphere. If I push the cylinder down some past ... ### 2 How can I calculate the neutral buoyant weight of an airship at altitude? 1 answers, 393 views mass pressure buoyancy I love airships. I often like to do research on the old designs from the 20s and 30s. Trying to figure out how they work and how they're built etc. Lately I've been working on trying to calculate how ... ### Is it easier to lift an object in air rather than in vacuum? 1 answers, 99 views water vacuum air buoyancy fluid-statics I was reading about why lifting an object in water is easier then in air. The explanation goes on the line that the water which was above the object will fall downward and sideways, taking the place ... ### What will be the buoyant force on an object in an accelerating container? Our teacher taught us it is vρ(g+a) when accelerating upward. But I can't understand the reason for it. Isn't it vρg as buoyant force is equal to the weight of displaced fluid. Please help me with ... ### Can bodies of equal volumes but slightly different mass float fully submerged in a liquid (may be at different depths)? 2 answers, 57 views buoyancy fluid-statics Can bodies of equal volumes but slightly different mass (that is slightly different density) float (at rest) fully submerged in a liquid (may be at different depths)? Consider - At different depths, ... ### Terminal velocity and radius relationship in Millikan's oil drop experiment? 0 answers, 276 views fluid-dynamics velocity buoyancy viscosity After some research, I can see that Millikan (his original experiment) calculated the terminal velocity of oil droplets, and then used it to calculate the radius of since they were too small to ... ### -1 Why does oil float on water? This might be a silly question but I want to know why oil actually floats on water. I tried to explain it to myself using Archimedes' principle but that didn't help. Archimedes’ principle, ... ### Natural convection and buoyancy: What is a better description of$g\$?

In their derivation of the Grashof number (Gr), Çengel and Ghajar make the following comment: Note that there is no noticeable gravity in space, and thus there can be no natural convection heat ...

### 4 Would a Helium powered balloon vehicle work on Mars?

Would a Helium powered balloon vehicle work on Mars? Things that might need to be answered: How much liquid Helium would you need to pack in order to fill a balloon with enough helium gas to travel ...

Why is it physicists & engineers believe the hydrostatic paradox, (force exerted by a liquid is based on the internal pressure, which internal pressure is a function of depth) and thus that a ...

### Buoyancy on the Moon

1 answers, 487 views newtonian-gravity buoyancy moon
A body is floating partly immersed in a liquid. The body and the liquid are taken to the Moon. What will happen next? Will its immersed part come out of the liquid? Will it sink? Will it continue to ...

### The helium balloon and buoyancy

Well I noticed something with a helium balloon which a little weight was tied to its rope to avoid it flying away. When the weight is on the ground and the rope is taut, I pulled it down a little and ...

### Can we fill a balloon with gas and make it electric charged so it lighter than air?

0 answers, 28 views electricity charge buoyancy
Suppose we have a membrane that not chemically react to make a balloon and we seal airtight then steal electron from gas atom inside to make it positively charged and repel each other. Is it possible ...

### 4 No buoyancy inside liquid [closed]

1 answers, 276 views buoyancy fluid-statics
The answer to this question is given as (a) 5m. Due to the difference in pressure at the curved parts there will be a net upward force of buoyancy. And how can that be calculated without knowing the ...

### 1 How to measure buoyancy of multiple items at home (without fancy lab equipment)

I am a scuba diver and, hence, need to take into account how buoyant the materials are I take with me into the water. Given that I have a LOT of diving equipment, it is practically impossible to test ...

### Permanent flying balloon

We all know balloons which are filled with gas that's less dense than air. After a few hours, the balloon drops to the ground. The reason for this phenomenon, as far as I understand, is that the ...

### 2 How can buoyancy lift an object if the object is resting on the bottom? [duplicate]

1 answers, 174 views buoyancy weight
The situation I am thinking about is that, for example, lets say that there is a block that weighs 10N outside of water, when it is put into water its apparent weight is 2N. From this it can be ...