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2
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1answer
57 views

Is Magnus effect a corollary of Bernoulli principle?

Magnus effect is commonly explained using Bernoulli principle. However, taking the lift on a rotating cylinder as an example, the velocity difference is caused by the extra work done by the rotating ...
0
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2answers
19 views

Microscopic definition of dynamic pressure of fluids

So we have a moving fluid and we know from Bernouli's equation that there is a term called dynamic pressure(not to be confused with the hydrostatic pressure of the fluid). So,what exactly is it and ...
0
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1answer
24 views

What is the difference between high speed water supply and high pressure water supply coming out of a hose?

According to Bernoulli's principle, $P + \frac{1}{2} d v^2 + dgh = constant$ where, P is pressure, d is density of water, v is velocity and h is height. Assuming that height of a plastic pipe is ...
0
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1answer
23 views

Liquid Flow Over Object

When there is a large object in the bottom of the ocean of height h, the surface of the ocean rises by a height less than h. In fact, if the ocean depth >> h, then the surface will rise negligibly. ...
0
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1answer
42 views

How can Bernoullis be solved without Vectors [duplicate]

Some time ago I asked a question why Dynamic pressure is considered scalar. Why is the dynamic pressure not a vector quantity? This still puzzles me so I hope to give a scenario that doesn't make ...
0
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0answers
22 views

Tank draining with piston

I am trying to solve a problem which is close to the tank draining (as here Fuel tank draining) but with a piston a the top of the tank which means $p_A$ different of $p_B$. I search the velocity ...
2
votes
3answers
101 views

What is basically the difference between static pressure and dynamic pressure?

What is basically the difference between static pressure and dynamic pressure? While studying Bernoulli's theorem, I came before these terms. The law says: When the fluid flows through a small ...
1
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1answer
142 views

Application of Bernoulli's theorem

My teacher told me the following examples of Bernoulli's principle. I didn't understand how Bernoulli's principle is applied in these examples. It is dangerous to stand on edge of platform when ...
0
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1answer
30 views

Does using Bernoulli's equation for a region of zero mean flow violate mass conservation?

Let's say I have a pressure reservoir with zero mean flow connected to a pipe with mean flow. So for the reservoir we have $p_1>0$ and $v_1=0$. For the pipe we have $p_2,v_2>0.$ Bernoulli's ...
1
vote
1answer
64 views

Equilibrium between two water tanks

I've been reading about hydrostatic theory, however I couldn't find a similar case/exercise about my basic problem. I have two water tanks (same size) filled with different water heights, and ...
-2
votes
1answer
54 views

Find the discharge Q. Pipe flows [closed]

Trying to work my way through an example in my course notes on fluid flow in pipes and I'm really stuck on where to start. The question is as follows; A pipeline 10km long and 300mm diameter with a ...
1
vote
1answer
77 views

Compute pipe restriction from water flow and static pressure

How can I determine if residential water pipes have a restriction given, for example, flow rate and static pressure? Details: (1) You hook up a static pressure gage to a faucet which is in the ...
0
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1answer
71 views

The Bernoulli equation: positive and negative sign problem

According to bernoulli equation $$ P_1+1/2 \rho v_1^2+ \gamma h_1= P_2+1/2 \rho v_2^2+ \gamma h_2. $$ Because $$ v_1=0\quad h_1=0 $$ So $$ 0= 1/2 \rho V^2+ \gamma h. $$ It is wrong I know, but ...
2
votes
1answer
143 views

Is the change in cochlear potentials dependent on perilymph velocity? [closed]

context: This question may appear to be off topic because it is about the biological particulars of the human ear. Physics can solve abstract models inspired by living organisms, but it is biology ...
0
votes
0answers
19 views

Would a solid inside of a parcel moving due to buoyancy be affected by Bernoulli's Principle?

If a parcel (or column) of hot air were rising due to buoyancy and an extremely light solid were to be inside of this parcel (rising with it), would Bernoulli's effect cause the solid to stay inside ...
4
votes
1answer
349 views

Fuel tank draining [closed]

A cylindrical fuel tank is being drained from the bottom as in this picture : Conservation of flow rate : $v_A = \frac{S_B}{S_A}v_B = \alpha v_B$ Assuming that $z_B = 0$, Bernoulli's theorem ...
2
votes
1answer
147 views

Why is the dynamic pressure not a vector quantity? [duplicate]

I understand that static pressure is a scalar quantity as it acts equally in all directions, then by the same reasoning dynamic pressure should be a vector quantity as it only can be measured by ...
0
votes
1answer
41 views

Calculating velocity from a pressure distribution

Using computational fluid dynamics I have calculated the pressure distribution over a streamlined body. I have access to the static, dynamic and total pressure seperately and assume that I can use ...
3
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1answer
182 views

Intuitive meaning of a special case of the Bernoulli equation

In the Bernoulli equation, if $h$ equals zero, it reduces to $$P_1+\frac12\rho v_1^2 = P_2+\frac12\rho v_2^2$$ The equation does not have an intuitive meaning other than the fact that it is a bare ...
0
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0answers
30 views

Airfield Windsock

Why don't windsocks collapse? It would seem Bernouilli would say otherwise. But we know empirically that they don't. Proof:Visit any airfield. So the air in the sock must be going slower right? I ...
3
votes
1answer
115 views

Bernoulli's equation for flow between cylinders

Let's consider the situation bellow noting that the water cylinders aren't equal and there will be water flowing to the right (As indicated by the arrow) Taking Bernoulli's equation at the tip of ...
1
vote
0answers
205 views

Pressure required on a wing to lift a plane and the speed required to create this pressure difference [closed]

An aircraft has a single wing with a total area of A =1 2.6 m2 (assume that the thickness of the wing is negligible). When in motion, the air flows under the wing at the velocity that the aircraft ...
1
vote
1answer
143 views

Bernoulli Equation Paradox

Imagine a funnel with an extremely wide mouth, filled with water. Attached to the stem is a water pump that pumps water upwards (into the funnel). Water is being pumped in at the rate of Q. The cross ...
3
votes
4answers
442 views

Is a causal relationship implied by Newton's 2nd Law?

Throughout my time learning physics I have been imbued with the notion that forces cause accelerations, period. Accelerations don't cause forces, and they aren't merely correlated phenomena. By ...
0
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2answers
157 views

Definition of pressure in Bernoulli's principle

I have a difficulty to understand Bernoulli's Principle which states increased fluid speed decreases the pressure. But in a wind tunnel when we measure the pressure with a pitot tube, both the ...
6
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1answer
205 views

Problem understanding basic sail mechanics

I am trying to understand the physics behind a single sailed boat. I have read the following questions Sailing against the wind. Is this a fair model? What exactly is the 'lift' of a ...
2
votes
1answer
217 views

Feynman's derivation of Bernoulli (part of it)

OK, so what's up with the $\Delta M$ here? I don't get it. In fact, my textbook doesn't even put it in. I don't think it is a type-o because he continues on with the explanation. If anything I got ...
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vote
0answers
105 views

Bernoulli's equation

So there's a pipe filled with water that has 4 other pipes with same radii connected to it. The question is to arrange heights from the smallest to the biggest level in it. $A_1$ and $A_2$ are ...
0
votes
2answers
178 views

Pressure $p$ in the Bernoulli equation

I know the Bernoulli equation that states that the energy along a streamline is constant: $$ \frac{v^{2}}{2}+gh+\frac{p}{\rho}=C $$ However I can't seem to figure out what exactly $p$ is in this ...
1
vote
1answer
185 views

Bernoulli's principle

In steady flow, the air that flows faster causes a lower pressure, the lower pressure causes it to move faster, or exactly both at the same time? Also how is it that we're talking about the pressure ...
2
votes
2answers
289 views

Can the lift generated by a helicopter be justified using Bernoulli theorem? [duplicate]

When the shaft of the helicopter rotates, it creates a low pressure. Because of the low pressure, the helicopter lifts. Is my understanding that this is just an application of Bernoulli's theorem?
5
votes
1answer
323 views

Pipe in a flowing river problem

I'm working on a certain problem in fluid mechanics, which isn't really my strongest area. The problem is as follows: Curved pipe is partially submerged in a flowing river so that one end is pointing ...
2
votes
2answers
94 views

Air pressure in closed (circular) tube

I have learned that for fluids and gases $P_\text{total}=P_\text{dynamic} + P_\text{static}$. Suppose we have a closed circular tube in a form of ring filled with air under some pressure. In this ...
0
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1answer
188 views

Maximum liquid velocity in a siphon

According to wikipedia: Siphon, the velocity of liquid in a siphon is equal to $\sqrt{2gh}$, where h is the difference in level between the water surface and the opening of the siphon. But it also ...
0
votes
1answer
1k views

Problem with Velocity of efflux [closed]

I am stuck in this problem- I need to find the velocity of efflux at the hole of the container. [We can assume that the area of the hole is negligible in comparison with the base area of the ...
3
votes
2answers
1k views

What exactly is the 'lift' of a sailboat as explained by Bernoulli principle

I have heard that when a sailboat is sailing against the wind, it operates on the principle of 'lift'. I am unable to understand the explanation, based on Bernoulli principle, completely. My question ...
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3answers
838 views

A question on Bernoulli's principle

Which is more appropriate regarding Bernoulli's principle fast moving air causes low pressure or lower pressure causes fast moving air.
3
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1answer
341 views

Static pressure of free air stream

One of the common misunderstandings regarding Bernoulli's principle is that, in general, "faster moving air has lower pressure". Bernoulli's principle can only be applied to asingle streamline in ...
0
votes
2answers
284 views

Why doesn't Bernoulli's Principle apply to Current and Resistors in a circuit?

Bernoulli's principle makes sense when you apply it to fluids. If you decrease the diameter of a pipe then the velocity of the fluid increases because it needs to keep the same rate of fluid moving ...
2
votes
2answers
449 views

What does the height refer to in the Bernoulli equation?

What does the height refer to in the Bernoulli equation? I'm trying to determine the pressure on a surface where the length is short enough that the velocity should be constant across it. Fan -> ...
6
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1answer
526 views

Question about the Bernouilli equation

There are some things I encountered, studying the Bernouilly equation, that I don't understand. I was studying in the following book: ...
3
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2answers
1k views

The pressure in a water spout and Bernoulli's equation

This is a conceptual question about the application of Bernoulli's equation to a water spout. There is a classical problem found in many physics texts which goes something like "you have a garden ...
4
votes
1answer
430 views

Compressible fluid flow through a branched pipe junctions

Backdrop: Designing a dust extraction system (LEV) with a branched junction. What principles allow for the calculation of volume flow rate and pressure at the inlets if the volume flow rate and ...
1
vote
3answers
46k views

Relation between water flow and pressure

Is there any equation that states the relation between pressure and water flow. I.e. Let's say that in 1 hour with 8mca (water collum meters) pressure I obtain 50m3. What if (giving the same ...