The Stack Overflow podcast is back! Listen to an interview with our new CEO.

Questions tagged [fluid-statics]

The tag has no usage guidance.

841 questions
Filter by
Sorted by
Tagged with
28 views

Why does dust form islands on top of water? [duplicate]

When you pour sand into water, first the dust particles that are floating on the surface, are separately all over. Then as the water flows, the dust particles should just randomly move around staying ...
35 views

Fluids Question [on hold]

I tried solving this by calculating the drag force on the point mass using the formula $F_d=\frac{1}{2}C\rho Av^2$ but I’m confused because it does not give the area but yet the volume of the mass and ...
50 views

Which direction a wooden cube would float in water?

If you place an uniformly dense wooden cube in water, would it float: face up vertex up edge up And why would that be the case?
15 views

Is Coefficient of viscosity frame dependent? Why/Why not?

Is Coefficient of viscosity frame dependent? Why/Why not?
27 views

Reynold's Transport Theorem explanation [closed]

Can anyone help me to understand the passages in this theorem, I'm trying to resolve it but it's blowing my mind
26 views

Perpetual Motion Explanation [duplicate]

Hello could someone explain the reason why this machine does not work. There is an explanation in the text but I cannot seem to follow it. Here is the link - it's the buoyant spheres perpetual motion ...
16 views

22 views

Increasing the pressure inside a diving bell

Is it physically possible to increase the pressure inside a water diving bell so that it exceeds the pressure outside it while submerged by allowing water into it?
27 views

Pressure between interface of two liquids?

Why is the pressure between the interface of two liquids is same?
34 views

Would a rigid object thats slightly negative buoyant sink all the way to the bottom of a 10,000 ft fresh water lake?

Would a rigid object thats slightly negative buoyant sink all the way to the bottom of a 10,000 ft fresh water lake? I'm going to make a few questions regarding the topic involving a submarine & ...
26 views

A basic question of positive buoyancy,

Positive buoyancy occurs when an object is lighter than the fluid it displaces. The object will float because the buoyant force is greater than the object's weight. But I also read, buoyancy ...
16 views

Liquid surface tension and molecular motion inside

In some of the descriptions I have found about surface tension, while they explain the phenomenon for liquid in an open container they use the following arguments: 1) A molecule at the surface feels ...
28 views

How do I calculate how much weight is needed to sink a specific amount of air and for how deep will it sink? Understanding buoyancy

I'm trying to understand buoyancy so I created a question that should help me greatly. To keep this simple my above is a photo is of a 20 ft long tank. Each line represents 1 cubic ft which each holds ...
25 views

If a see-saw was filled with fluid and is at an 80 degree angle would the see-saw act exactly the same as if it were completely solid?

I'm trying to understand the 'Lever Principle' and have made up a few questions to help better understand the concept. Although researching the subject I'm having troubles finding any videos or ...
63 views

Lattice Boltzmann Method: How is shear flow handled in D2Q5?

I've implemented 2-dimensional, incompressible, high-reynolds fluid-flow using the Lattice Boltzmann Method on a D2Q9 lattice. My main goal is just visual plausibility, not quantitative accuracy. The ...
20 views

“Pascal's Principle” hydraulic lift is (F1) the equilibrium to (F2) or alike to the “See-Saw Principle” is (F1) lifting (F2) past equalibrium?

I've been trying to understand "pascals principle" and thus far have learned a lot thanks to this forum. I have a few more questions regarding the topic so along the way please correct me if I'm wrong....
80 views

Hydrostatics and Buoyant Force

In the below problem the weight of the rod acts at it's centre (the centre of mass). But how do I know from the buoyant force acts? How do I proceed with the rest of the problem? Here's my attempt to ...
19 views

Pressure on a fluid element

We consider an element in a liquid at hydrostatic equilibrium such that continuum is maintained. Now to calculate the forces on it we consider body forces and surface force. Our system is simply a ...
63 views

Understanding the Hydrostatic Paradox in a tilted tube

I simply do not understand how point P2 can be at the same pressure as point P1. As I understand it, the pressure at those points is due to the column of water directly above the point. Well, in a ...
62 views

Would 200 lb of water thats 150 ft high lift more than 200 lb due to the weight + the extra pressure of the fluid being so high up?

I'm trying to understand Pascals principle in more detail so I made a drawing with a question to find out a segment of the differences between pressure and weight. As demonstrated in the project "...
51 views

Would it take an equal amount of lb-force as the total water weight weighing down on the piston to be at equilibrium? Pascals principle

Pascals principle sounds simple, but I'm a bit confused on this. A cylinder that's 24" in diameter by 5 ft in height filled with 117 gallons(980 lb) that's connected to 1" diameter pipe going up ...
60 views

How to explain the isotropic nature of pressure?

Shown in figure is a pipe in which a fluid is static. The pressure at A is equal to pressure at B since it is at the same level and pressure is isotropic. The pressure at A could be defined as the ...
58 views

Why is pressure in a fluid lower where velocity is higher? (Without using Bernoulli's equation)

So, it is said that wherever the velocity of the fluid is lower, the pressure is higher. I don't know see how this is reasonable. Can someone please explain this to me without using Bernoulli's ...
10 views

Water propulsion: Use air and rigid form to make waves feasible or not?

I had an idea that if you took a piece of material shaped like corrugated steel and positioned it such that the runs were horizontally oriented, attached it to the back of a water craft to span the ...
16 views

Variation of pressure of fluid in motion

As we all know that for a static fluid, pressure increases as we go down from its free surface. What about fluid in motion? Suppose I eject a jet of water in the air, parallel to the surface of the ...
81 views

Why the submarine sinks into the bottom of ocean once it starts to sink?

An inflated ballon will rise yo a definite height once it starts rise where as a submarine will always sink to bootom of ocean once it starts to sink, if no changes are made. How then can a submarine ...
43 views

Gas pressure in an container that is almost full of liquid when the liquid is pressurized

What happens to the pressure of some gas, air for example, that is in a container almost full of liquid, some hydraulic fluid for example, when the liquid is pressurized? The air is at 0 PSIG at the ...
68 views

Why the force exerted by a fluid on an object submerged in it is always perpendicular to it's surface? [duplicate]

When an object is immersed in a fluid, say or example water, then the force exerted by the fluid is always perpendicular to the surface. I'm unable to understand why is this so? My books writes :- (...
53 views

Is it possible to have no pressure gradient in a tank? [duplicate]

If a sealed container that is 20 miles high is filled to a pressure of 50psi gauge pressure, will it have a pressure gradient the same as the Earth or does the fact that it is filled to more than ...
39 views

Vacuum balloon / airship with balloons as shell segments

What are the problems with the following idea for building a vacuum balloon / airship? The question is targeted at the "making it float" part, ignoring other problems with super-light airships (...
61 views

I can't prove the Archimedes' principle in a particular case [duplicate]

If I put the cylinder on the bottom i replace F2 with normal force N. But it will be at most equal to F1 plus the cylinder weigh N=F1+$\rho$gV. So how can it get a bigger boost from the bottom to be ...
112 views

Ice Melting with a Twist [closed]

The Question There are three ice cubes floating in three different cups of water. In the first cup, the ice cube has a pocket of air inside. In the second cup, the ice cube has a pocket ...
28 views

Bird Transport Phenomena

in the book " transport phenomena" (Bird) when obtaining the famous equation of hagen poiseuille Bird defines a variable that involves the pressure, but when doing an exercise a term magically ...
40 views

How do I calculate the pressure $p_0$ on top of the water reservoir?

Can anyone help me with this question, I can't get the right answer :-) A water reservoir with depth D=200m, which is placed H=500m above on a mountain. A pipe is placed from the bottom of the ...
36 views

From what point is the hydrostatic pressure formula not valid anymore?

The hydrostatic pressure formula (P=p.g.h) is used (eg) to calculate the pressure at the bottom of a container. Now this pressure is equal independent of the mass in it as long as the bottum surface ...
31 views

Is it possible to find the exact value of the dynamic viscosity of a fluid by applying Stokes' law?

I am a high school student who is investigating the dynamic viscosity of a fluid. Typically, high school physics model the dropping of a spherical object vertically into a viscous fluid with the ...
33 views

Obtain an expression for pressure difference [closed]

The question is "For the two-liquid manometer, shown below, obtain an expression for $p_1 – p_2$. Let $\mathcal A$ be the area of each tank and $\mathcal S$ the area of the tube. Let $S_3$ be the ...
36 views

The definition of control volume regarding fluids

I haven't seen a clear and general definition of control volume. So if you know one, skip the context below and please give me your definition and sincerely, thank you. Context: The union of all the ...
34 views

How can you calculate the total time taken for water to completely flow out of a container given the amount of water initially in the container?

I'm doing an experiment on changing the amount of water in the container and seeing how the time is taken changes with it. The container has a little hole at the bottom where the water flows out from. ...
22 views

Would I have to add any additional weight at the end of the lever of well pump (B) for it to lift the same amount of water as did well pump (A)?

The question is if I would have to add any additional weight at the end of the lever of well pump (B) for it to lift the same amount of water as did well pump (A)? My assumption is yes because of ...
22 views

Buoyant force on partially submerged object

Is the force exerted by the liquid, in which the object is floating, same as the buoyant force exerted by the liquid? I am confused since the object is assumed to float with some part of it above the ...
55 views

Why is there an upthrust?

Why is there $P_2$? Is it because by Newton's third law of motion, $P_2$ is there due to the pressure of water column of $0.7 ~m$ above the bottom.