3
votes
2answers
114 views

How to calculate pressure loss due to water leakage from a hole in a pressurized unit

I am trying to develop a method for calculting the rate of pressure loss from a small hole in a pressurized vessel full of water (small air pocket likely at top of vessel). I've found a formula for ...
2
votes
2answers
117 views

what is the static pressure in a yield stress fluid?

Suppose I have a tank filled and there is no slip at the walls. If the tank is filled with a Newtonian fluid and is in static equilibrium, we know that the pressure is defined as $p = \rho g z$. But ...
0
votes
1answer
59 views

What is “hydrostatic uplift pressure”?

I was reading Wikipedia about the St. Francis Dam and came across this sentence. Water that collected in the drainage pipes under the dam to relieve the hydrostatic uplift pressure was carried ...
5
votes
1answer
121 views

Why is the pressure on top of a slab of water greater than the pressure on the bottom?

In the image below, my book seems to be saying that if you have a cup of water in complete equilibrium, then if you have a small cube of water inside the cup given by $dm=ρAdy$ there is a downward ...
1
vote
2answers
115 views

What is a good model for computing water dropping on a surface?

Before introducing my question I would like to outline the fact that I'm a coder, so I can be wrong when using some kind of terminology. What is a good model for computing the flow, the shape and all ...
78
votes
8answers
9k views

Why does a helium filled ballon move forward in a car when the car is accelerating?

I noticed that when I had a helium filled, latex ballon inside of my car, it moved forward in the cabin as I accelerated forward. The faster I accelerated forward, the faster the ballon went from the ...
2
votes
2answers
2k views

Why should fluids be confined for Pascal's Law to be applicable

When is Pascal's law about fluid pressure propagation applicable? Is it applicable to a closed circular pipe with a pump rotating the fluid, but not to a tub of water. Most statements require only ...
3
votes
0answers
152 views

Bubble in a pipeline

I am just thinking about this phenomenon: We have a horizontal pipeline with a flowing liquid, which contains a small bubble of gas. How do the dimensions of this bubble change when it reaches a ...
1
vote
0answers
130 views

Horizontal Capillary Question

I have a fluid mechanics question, that I think is caused by a lack of understanding of some key concepts. Suppose we have a horizontal capillary with a radius of 10um. The fabrication process has led ...
5
votes
1answer
672 views

Does something like Pascal's Law apply in a Swimming Pool? If not, how does pressure spread?

I've been trying to wrap my head what happens when a force is exerted on the surface of a swimming pool / pond, or underneath it. Examples include a small boy cannon-balling into the deep end, or a ...
6
votes
2answers
468 views

Hydrostatic pressure on a teapot spout

The phenomenon where water flows on the outside side of a teapot spout is named "The teapot effect", and occurs due to a difference in pressure between water and the atmosphere. Consider the image of ...
1
vote
1answer
378 views

Calculating pressure in accelerated fluids in closed and open vessels?

The question asked was "what should be the acceleration such that the pressure at both the points marked by thick dots be equal? the vessel is open and cubic with side 5m?" Initially i considered ...
2
votes
1answer
149 views

Sideways motion between a vertical launch from a planet and landing [duplicate]

I saw a video some days ago (Hello Kitty in Space) of a schoolgirl successfully launching a balloon into space which later popped and landed ~47 km from launch site. If I vertically launch an object ...
2
votes
0answers
84 views

Stat mech explanation for separation of one liquid from another in gravity?

If one mixes two distinct ideal gases above the Earth's surface, one with a higher molecular mass than the other, then at equilibrium, their number density gradients will be such that at low heights, ...
3
votes
5answers
301 views

How can the surface of a liquid exist if there are no attracting molecules above it?

Okay this is probably a stupid question but here goes: We know that molecules in a liquid are attracted from all the molecules around it so there is no net attraction. Well, then how do the ...
7
votes
2answers
378 views

At what velocity does sea water leave a pipe run into a fresh water lake (for equal surface levels)?

If I took a fresh water lake* whose surface is exactly as sea level, and connect it to the sea with a pipe filled with sea water, with both ends of the pipe at exactly the same depth from the surface, ...
4
votes
4answers
3k views

How far can water rise above the edge of a glass?

When you fill a glass with water, water forms a concave meniscus with constant contact angle $\theta$ (typically $\theta=20^\circ$ for tap water): Once you reach the top of the glass, the water-air ...
3
votes
2answers
523 views

Need help understanding dynamic and static contact angles

I've run into a conceptual road block. I'm coming to you guys because I think my adviser is getting annoyed with me. The concept involves a meniscus being pulled up a cylinder. I understand that ...
4
votes
1answer
429 views

Why do sea levels not rise uniformly around the world?

While reading the article Hawaii’s Beaches Are in Retreat, and Its Way of Life May Follow on The New York Times's website, I was surprised to find out that sea levels do not rise around the world at a ...
1
vote
1answer
118 views

Surface tension of N non-mixing fluids

I am a mathematician, not a physicist, so please be gentle with me if I write something wrong. Consider a bounded, regular container $\Omega$, which is filled with the fluids $F_1,...,F_N$ which do ...