# pressure's questions - English 1answer

1.703 pressure questions.

### Calculate pressure drop in nozzle with liquid plastic

0 answers, 5 views pressure liquid-state
In 3D printer liquid plastic flows with pressure through nozzle. P1 is initial pressure, maked by motors, P0 is atmospheric ...

### -1 Shape of an aircraft window [on hold]

Consider question 10.3 in http://filestore.aqa.org.uk/resources/physics/AQA-84632H-SQP.PDF This is how far I have got on the question:- 1.Pressure(inner)>Pressure(Outer) 2.Area(inner)>Area(outer) ...

### Inverted Water Dispenser

My head is exploding thinking about this. Consider the water dispenser below. The upper bottle is squeezed and inverted. My question is, will it rebound gradually to its cylindrical form? Or will it ...

### 1 Why is steam-cooking slower at higher altitudes, where water boils at a lower temperature?

2 answers, 192 views pressure temperature water
This question comes from a chemistry test that i got back. I'm posting this on physics.stackexchange because i feel that i don't get the physics side of it. We learned that temperature increases the ...

### 1 isothermal compression of water and definition of temperature

During isothermal compression of water vapor (below critical temperature), the pressure increases initially, and then remains constant up to certain point, and then steeply increases with small ...

### 2 Is presure inversely related to velocity?

. I’m not sure if that picture worked or not but it’s a question from my textbook that was asking what factors would cause velocity of blood in an artery to decrease. It says in the answer at the ...

### 1 Mathematically calculate heat capacity in varying pressure and volume conditions

1 answers, 48 views thermodynamics pressure
I understand that the heat capacity depends on depends upon both microscopic (molecular/atomic) and macroscopic (phase, temperature, pressure). If I have an environment wherein both - the pressure and ...

### 2 What is fluid pressure?

I cannot understand the concept of fluid pressure. Consider a liquid molecule at some point inside a liquid vessel. All the other molecules which are in contact with this molecule will exert normal ...

### 1 Static pressure in a multi phase suspension

1 answers, 17 views fluid-dynamics pressure fluid-statics
I have a headscratcher: Suppose you have a suspension, say sand dispersed in water. Looked at as a bulk, over the whole volume, the density would be higher than water. Do we expect a higher pressure ...

### -2 Does lightning have pressure?

Hi do lightning have pressure if yes what is it ? Nikola tesla has invented the artificial lightning so can we make it ?

### What happens if a cylinder filled with propane gas is connected to an empty one of the same size

2 answers, 1.500 views fluid-dynamics energy pressure
Let's say I have $2 100$ lb propane cylinders. One of the cylinders is filled to its maximum capacity while the others are empty. If I connect them to each other via a high pressure hose in an upright ...

### pressure problem relating to basketball

I know that a basketball should have pressure between 7.5 to 8.5 pounds (51.71 kPa to 58.605 kPa) of pressure, according to NBA. However, the air pressure is less than 1 atm (101kPa). If the valve of ...

### Piezoresistive pressure sensors - how do they collect both temperature and pressure?

From my understanding, a piezoresistive pressure sensor can read current pressures by measuring the resistance of a piezoresistive material. That all makes perfect sense... until a piezoresistive IC ...

### 2 Will air push the water or pass through as bubbles?

This doubt is about a conundrum which is common to multiple scenarios. One such scenario is this: The valve is opened and the high pressure air is pushed towards the water in the channel with the ...

### 4 Is it possible to prevent water from cooling by keeping it in an rigid container?

7 answers, 160 views thermodynamics pressure temperature water
If you fill a soft plastic water bottle with hot water, close the lid, then cool the water down, the bottle will contract. When you open it up, it will expand again. Conversely, if you used a hard ...

### 2 Water pressure vs temperature

2 answers, 3.845 views thermodynamics pressure temperature water
If I have a sealed enclosure full of water (constant volume) at 25˚C at atmospheric pressure, I then heat the water to 50˚C. Would the pressure in the sealed enclosure change? If the pressure has ...

### Where will pressure be stronger in these 2 pipe scenarios?

I initially started to be interested in fluid pressure and pipes to learn electricity. It seemed the only way I could help my head to get around some electrical concepts. That's the reason of my ...

### Will flow ever reverse or stop if we increase resistance in this pipe scenario?

0 answers, 33 views fluid-dynamics pressure water
This is the third question I decided to ask on this topic. I've received some beautiful and detailed answer in the previous posts, so if you want to take a look, you can do it here and here. The ...

### 3 What happens to the pressure inside a tied-off balloon as the pressure outside the balloon decreases?

I'm almost 100% positive it would decrease, but my meteorology professor (who also teaches physics) says it will stay the same, because no air is escaping the balloon! Does the rubber of the balloon ...

### 1 Submerge an upside down bottle into a ball of water in space

2 answers, 63 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 ...

### 3 Atmospheric pressure And heat convection

4 answers, 120 views pressure temperature convection
If hot air rises due to convection, why does it get colder when we climb mountains? After some research, I found out that atmospheric pressure affects the temperature of the surroundings. Another ...

### 4 Effect of aircraft speed on barometer

Many aircrafts depend on several types of static pressure sensors (barometers) to find the altitude. I assume this sensor need to be located outside the aircraft main body, so that it has a contact ...

### 1 Hydraulic analogy and pressure in pipes

In the latest days I've been quite obsessed with understanding how electricity work through the hydraulic analogy. I still have some problems regarding how "voltage drop" works, and how pressure drops ...

### 2 Pressure in Scott Dodelson's book Modern Cosmology

I am completely at a loss in deriving the equation 2.62 given in Scott Dodelson's Modern Cosmology book. That is the following expression for the pressure of Fermi-Dirac and Bose-Einstein ...

### 2 Density solver for ideal mixture of real gases

1 answers, 273 views thermodynamics pressure density
I am referring the paper on GERG-2008 equation of state. I am interested in calculating the properties of ideal mixtures of real gases. The GERG-2008 EOS is in Helmholtz free energy and hence the ...

### -1 How powerful can the vacuum from an open aircraft window be?

2 answers, 56 views pressure bernoulli-equation aircraft
It has been an item of folklore that a "pressurized" aircraft cabin, if punctured will force people through the aperture, a la Goldfinger. However, obviously the pressures inside the cabin (12 PSI) ...

### Does the internal pressure of Mercury-vapour gas filled tubes increase when they are excited?

As I understand it, the mercury-vapor lamp uses a form of non-thermal plasma. I read that the 'electron gas' temperature can reach 20000K but the actual temperature of the tube itself is only slightly ...

### 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 ...

### Relationship between velocity and pressure of a fluid in motion

2 answers, 43 views fluid-dynamics pressure
I'm confused about the relationship between the velocity and the pressure of a fluid in motion. According to Bernoulli's equation, mathematically when the velocity increases the pressure has to ...

### Emptying two water tanks at different levels with priority through same outlet pipe

The requirement here is something related with emptying two water tanks at different levels giving priority to one over the other. Real life scenario hers is about usage of harvested rain water which ...

### 2 How does the vertical distance beneath the surface of a fluid create pressure? (thought problem)

4 answers, 376 views pressure hydrostatics
Specifically, I am trying to wrap my head around this scenario but can't do so solely by thinking about the weight of the fluid. Imagine a perfectly still lake. If you dive into the lake, the ...

### 1 A water balloon in vacuum: does it boil?

1 answers, 1.303 views water pressure vacuum
If I put water in a vacuum it will boil. But what if I put this water inside a balloon ? I searched for answers and fount this video: http://www.youtube.com/watch?v=9q8F3ClUuV0 It appears that the ...

### 1 Can pressure increase rusting rates?

Most everyone knows how rust is formed but just to remind you when iron is exposed to oxygen and moisture for extended periods of time. Now if we were to apply much more pressure to the environment ...

### 1 What is an experiment to teach my daughter about steam (water) pressure?

On a recent steam train trip my daughter said to me: Daddy, I'd like to pull that steam engine apart and see how it works. Now there are two parts to her question - and I'm only make this physics ...

### Will flow rate always increase if the pressure drop across piping system is decreased?

3 answers, 1.340 views fluid-dynamics pressure flow
I have a test stand that is used for testing hydraulic pumps. We are adding a pump that we have never tested before and we are getting low flow readings. Will increasing piping to one size bigger than ...

### 2 Rankine Cycle pressure

I don't understand why in (Ideal) Rankine Cycle we assume that pressure remains constant at the boiler and the condenser. Shouldn't water pressure change, when water goes from liquid to vapor (boiler) ...

### Understanding Fluid flow- Am I right or the book?

I was solving this question :- And according to Me H=10cm is the answer. But the book says this:- Now , I don't understand **why does the liquid fall quickly on reaching top right corner?? ** One ...

### How do scientists measure vapor pressure?

Experiment: We have a cylinder with a piston that is essentially weightless, frictionless, and exposed to atmospheric pressure. The cylinder has a volume of 2V, but half of it is filled with water and ...

### 9 Can you make a metal denser by melting it and make it cool down under high pressure?

The answer is probably no. But can you make a metal denser by melting it and make it cool down under high pressure? Or would it just crack under internal stress when it returns to a solid? I'm going ...

### 1 Flow rate of gas down a pipe at low pressures

1 answers, 626 views pressure ideal-gas kinetic-theory gas

### 1 Reducing water pressure

1 answers, 266 views pressure water
If water pressure and volume are proportional as another question and answer seem to suggest, why can't I reduce my home water pressure by just partially closing the main water valve to my home water ...

### 3 Hot air balloon - mass

2 answers, 664 views pressure density
Short background I'm aware that a hot air balloon rises up because of the less density than air. But I'm not sure about how that lower density is reached, and how it can be sustained over time. At ...

### Enclosures & Air Flow

1 answers, 11 views pressure air flow
Imagine you have a box, initially fully sealed with an electronic component generating heat. You create a small hole at the bottom and a large hole at the top. What effect does this have on airflow ...

### Pascal law: perspective from newtons law and forces

2 answers, 29 views newtonian-mechanics pressure
Pascal law says, conceptually, that exerted pressure is transmitted equally to all points on a fluid. The so called example of hydraulics, where force gets amplified, is an application of the ...

### 1 How to get the pressure amplitude at any spatial point?

1 answers, 363 views waves pressure acoustics
Working on the pressure equation from the linearized euler equations, I stumble across a very simple problem : How, from the pressure solution of the specific equation (see http://www.acs.psu.edu/...

### How to calculate air flow from a pressurized tank?

I am writing an app that deals with simulated air brakes, and I need to simulate the release of air from one container of a given pressure into another container of a lower pressure. It doesn't have ...

### 3 Why is Jupiter gaseous rather than solid or liquid?

Why is Jupiter made up of gas? If the gravitational pull was strong enough would it compress to form a solid body?

### In an experiment, the transducer showed -1.9 Bar pressure. How is it possible?

2 answers, 41 views experimental-physics pressure
I was doing an experiment on water hammer in pipes. During the experiments, in several cases, the transducer reported negative pressure, as low as -1.9 bar gauge! But I have read that it is not ...

### How do I find out the net thrust produced by a propeller?

I am trying to find out the thrust that a propeller produces. Since a propeller can have various different types of inclination for it's blades as well as several parameters such as number of blades, ...