# Questions tagged [bernoulli-equation]

An equation governing fluid flow for an incompressible steady fluid

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### Torricelli's Law and Variable Density

I wish to explore a slight modification of a well known result found in several physics texts - Torricelli's Law of Efflux. The most common problem on the above result has the following setup: The ...
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### Floating sketchpen?

This post is about an experiment of mine , which was for me, remarkably interesting! Why do I post it here? I'm interested in knowing the physics behind this. MATERIALS USED A light weight ...
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### Deriving the expression for the height of liquid in a cylinder spinning on a turntable using Bernoulli's principle

When a liquid in a cylinder is spun on a turntable, it will experience a vortex or whirlpool effect, as shown below: I have seen and understood a proof for the value of $h$ by taking the motion of a ...
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### Bernoulli's Equation for flow of gas and changing area

My task is to determine the size of piping needed in a system. In this system, hydrogen gas flows horizontally in a $\frac{3}{4}\,\mathrm{inch}$ pipe and into a vertical pipe of a larger diameter. My ...
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### Solve unsteady state Bernoulli equation for flow in a pipe

I am an engineer studying an unsteady-state flow through a pipe. The Pipeline has been cleanly cut into two halves, without deforming the cylindrical form of the pipe, exposing the contents to ...
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### 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 ...
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### 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 ...
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### Flow through a hole in a sphere

I have a sphere of diameter $D$ (radius $R$) with a small hole of diameter $d$ (radius $a$) in it, with air flowing through the axis of the hole: I am trying to estimate the drag force due to ...
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### 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 ...
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### Why does moving air have low pressure?

According to Wikipedia lift in an aircraft is due to an area of low pressure formed above the wings of an aircraft due to the fast moving air there. So why exactly is an area of low pressure created ...
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### Why do proofs of Bernoulli's equation assume that forces on opposite ends point in different directions?

I've read 4 different books and yet nobody explains why forces $F_1$ ($=p_1A_1$) and $F_2$ ($=p_2A_2$) point in different directions. Shouldn't $F_2$ point in the same direction as $v_2$? Since we'...
I am trying to calculate the outflow velocity $v_2(t)$ from the orifice of a funnel for water. I am aware of Torricelli's law derived from the Bernoulli equation assuming $v_1(t)\approx 0$ resulting ...