# Tagged Questions

Two Hydrogen atoms covalently bonded to one Oxygen atom. One of the more common compounds on the surface of the earth.

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### Is it possible to fight tree height limit with centrifugal force?

I heard tree has some height limit because water cannot be pumped over some height (130m if I remember it right) which cap the limit of tallest tree possible on earth But there are centrifugal force ...
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### Thermofluid mechanics, calculating load on a steel water tank

An open cylindrical water tank 2.4m diameter rests on three legs evenly positioned around the periphery of its circular base. The base and sides of the tank are made from steel with relative density 7....
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### What phase is water at 262C and 15bar? [closed]

what phase is water at 262C and 15bar? at which conditions and above can we be sure that the water is totally gaseous? can I see a water phase graph for 262C and 15bar?
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### Will it sink under circumstances? [closed]

I'm a 10 year old with a question. If you have a waterproof box the shape of a prism with an open top and you have a lid that fits perfectly in the top and you fill the box with water then put the lid ...
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### Why water's temperature is less than air?

I measured the temperature of water and found that it's less than room temperature. I think evaporation is the main reason of it. Are there any reason except evaporation for the less temperature of ...
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This is a deceptively simple problem in fluid mechanics that I can't quite figure out because it produces a paradox. Suppose that there is a straw and a small column of water inside the straw, such ...
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### The physics of a drying shirt

So, I've noticed this enough times to state my observations. I wash some shirts and hang them up to dry. Sometimes I need to wear one before they have completely dried. What I have noticed on ...
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### Heat transfer between water tank and room temperature

I have 20 gallons of water (salt water, but this might be irrelevant). These 20 gallons have a heater that maintains a minimum of 78º F. With the increasing temperatures during summer, the water ...
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### Submerged water jet

I am trying to calculate at what pressure and speed water from a high pressure water jet will hit an object 100 millimeters away from the nozzle opening, but i can't figure it out. The nozzle will ...
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### D2O distribution in water [duplicate]

I just learned that about 1/1000 of hydrogen is deuterium. Does that mean 1/1000 of water is D2O, which is heavier and sinks to the bottom in a glass of water? And consequently is there a layer of D2O ...
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### Would a world filled with water collapse?

I don't know if this is considered off-topic but, If you took a planet (assumed solid) and filled it with water continuously/non-stop what would eventually happen to the water? Would gravity at ...
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### How long time before all the water in a lake has been replaced? [closed]

Studying hydrology, and in that context we've seen some information about lakes and the times it takes for the water to renew completely in them. This got me interested in finding out how this is ...
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### How much salt to dissolve in water for a noticeable change in volume?

I am reading through this High School science lab about how dissolving salt changes the volume of water: Place 300 to 400 g of salt in the flask (1L) Pour in enough water to cover the dry salt, and ...
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### Average Rate of Evaporation of Water

Consider a container of volume $V$ and cross sectional area (exposed to another fluid, say air) $SA$. The container is at constant temperature $T$, and contains $N$ molecules of water, where $N$ is ...
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### effect of opening the barrier between a tube with one side pressurized and the other side a vacuum

What would happen when a tube with an air space pressurized to 500 atm by the water exerted at 5 km below the surface was opened into a vacuum chamber rising up 5 km to the surface? The bottom of the ...
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### Surface tension in a balloon wtih water [duplicate]

Imagine such situation: We have an empty balloon. We put a long, narrow tube into this balloon and we fill it with water. Then, the volume (and surface) of the balloon will start to increase. The ...
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### Can vaporization heat added to the whole volume of liquid before vaporizing it?

It seems, for example a volume of water is heated to boiling point, then part of the water is vaporized, while the remainder need much more heat to vapor, which means that part doesn't receive latent ...
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### Why Flow meters are some times showing -ve fluctuating Values in Pressurized Pipe lines [closed]

In our Underground Water reservior we are pumping water by Hydro-pneumatic pumps to maintain same pressure till last connection. in order to measure the flow we have installed precise electromagnetic ...
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### Why does water feel cooler than air?

My first assumption was based on "evaporation causes cooling" but I realized that it is not the case as it is cooler even if I am submerged under it. Are all liquids generally cooler than air ? Just ...
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### H2O Fuel of the Future [closed]

So I was busy trying to solve the world's problems the other day and a thought crossed my mind. I came across some data about cars that run on H2O and I was thinking that this seems like a great way ...
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### Optics of stationary waves

could anybody tell me how it Works if it comes to stationary waves created on the surface of water jet and optics? there are some crests and troughs which work like lenses, but if you have water jet, ...
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### Melting ice: reversible or irreversible?

I am looking into whether the melting of ice (or any substance for that matter) at constant pressure and temperature is reversible or irreversible. Different sources say different things, and it may ...
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### Water vs. Air : Heat Absorption/Capacity

I am not a physicist by any means and not even a current student, but nonetheless I am looking for an answer. Here is what I have gotten so far from university websites and other various resources on ...
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### Noncoalescing and bouncing droplets

if you set a dish filled with water onto a loudspeaker or other vibrator and make vibration, When it oscillates, it is possible to hold small droplets on its surface for a long time. I mean, when you ...
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### Water molecule Resonant Frequency

If water is subjected to microwave energy at the water's exact resonant frequency but 90 degrees out of phase, would the water molecule cease vibrating? Would the water then freeze or be cooled at ...
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### Why Counter waves are being produced in water?

While studying water waves in a cuboidal tank, the following observation was made. A gentle tap on one side (A)of the tank, generated waves from that side towards the opposite (B). At the same instant,...
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### What makes some air bubbles in water more persistent?

In a plastic bottle of water, near the walls, it is common to observe the presence of little bubbles (I would estimate them to be $\approx0.5$mm in diameter. In my experience, most of these bubble ...
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### Pumping water vapor into liquid water [closed]

Do liquid water and water vapor count as different types of matter? How does Second law of Thermodynamics apply when I pump water vapor into liquid water? What would happen when water vapor goes into ...
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### Why is water expelled more powerfully from a trigger hose the moment its triggered?

I think its something to do with acceleration but can't put my finger on it. Something about the most power needed as the greatest acceleration, as water flows up to full rate the accel and thus ...
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### How does air going through silica gel change its humidity

Assume that the properties(temperature,humidity,velocity and so on) of the incoming air flow stay constant. The air flow goes through a silica gel plate. Humidity of the air will decrease, but how to ...
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### Detect ions in water using impedance spectroscopy

I would like to check the presence of Na, Ca or other ions dissolved in water using impedance spectroscopy. I was thinking that because the ions have different masses they will have different ...
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### How much power is being actually delivered by an electric heater to a cooking pan?

I've been doing experiments on an electric heater heating a cooking pan filled with 2 litres of water, from 20°C to 70°C; now I'm trying to draw a theoretical heat transfer model thath should match ...
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### How does water height in a vacuum chamber effect pressure

I am testing for package leaks in non-porous packages. Quick details are: 1) Package is sealed at atmospheric pressure. There is some headspace inside the package which is just air. 2) A small hole is ...
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### Why do water droplets not form on large openings such as pipes?

When you have an object with a small opening, such as a pipette, water droplets form and hang easily. However, when you have a larger opening such as a pipe, the same water droplets do not form. Is ...
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### Why does microwaved water kill plants? [closed]

I've read tons of articles about microwaved water klling plants and the most of them said it was a myth. So I decided to do this experiment myself on cress plants. I repeated the experiment three ...
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### Is an “underwater” submarine affected by a nuclear bomb exploding above the water? [duplicate]

I've just read Would being underwater help survive a nuclear bomb?. Submarines are way more armored and far from the surface than a human body (https://en.wikipedia.org/wiki/Submarine_depth_ratings), ...
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### Is water boiling an excited state?

I was wondering and arguing (pro) with a friend that the process of water boiling is an excitation. I based my opinion on the theory that excitation is an increase in the energy level of an atom. I ...
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### Why doesn't the fridge condense water like an air conditioner? [closed]

Simple question, why doesn't the fridge condense water like an air conditioner? I know that my ac condenses water (even in cool or heat) and don't know why the fridge doesn't. Aren't they both ...
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### How many water wheel can fit on a river until another one produces zero energy?

Mostly what I'm after are the factors I need to know to do the problem. Imagine we're in the days of Leonardo Da Vinci. And pizza is everyone's favorite food. And there's a river that goes on ...
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### Force on sides of a pool [closed]

I am going to create a large pool of water for a stage production. The volume of water will be 6m x 5.2m x .15m deep. I want to check how much pressure or force will be exerted on the surrounding ...
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### Solving propulsion force of water rocket

As a note, I am not a physics student, although I am familiar with many physics concepts and calculations. I am trying to calculate the force of the thrust of a water rocket. I started with the ...
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### Best frequency for Underwater Transmission

What is the best frequency of transmission of under the water for communication with good data rate? I have read that the threshold of hearing underwater is around 170 to 180 db. Can this be useful in ...
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### By which factors are tides and waves affected?

To my understanding, the tides and waves on Earth's oceans are caused by various factors such as the moon's gravity, the water cycle (rains, storms, evaporation), Earth's rotation, etc. Although the ...
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### Simulating open water acoustics in a tube

For the purpose of testing an underwater acoustic transmission it is possible to use a tube filled with water with a transducer at one end and a hydrophone at the other. The problem is that sound will ...
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### How do buoyancy control devices (BCD) work?

I get that having more air decreases density and increases buoyancy. However, we can take the diver-BCD-oxygen-tank to be a single system. How can the pumping of air from the tank into a vest around ...
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### volume of the air bubble in the water

How does the depth affect the volume (the radius) of an air bubble in the water, if the temperature and density of the water are constant. Is there any relation combining this? Can I say that \$dh/dt=...
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### How quickly does the temperature rise in a water container submerged in a hot water bath?

Let's assume I have a small bottle (neglecting any insulation from the walls of the bottle) containing e.g. 150ml water at 4°C and place it in a larger pot with sufficient water at 80°C so that the ...
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### The impatient hot tub owner [closed]

An impatient man owns a 300 gallon hot tub. He comes home from a hard day of work and sees that his hot tub is currently simmering at 90F. For maximum relaxation, he wants it at 104F. However, the hot ...