Water Definition and 1000 Threads

This article has a different spin on how water came to Earth. https://www.newscientist.com/article/2118993-Earth's-water-must-have-arrived-here-earlier-than-we-thought/ The arrival of water on our planet wasn’t a last-minute job. Water came to Earth on icy comets after most of the planet and...

I'm trying to make two metal cylinders which will overlap to act as a valve for the outer cylinder to rotate around the other. I need to be able to stop water from the reservoir around the outer cylinder from leaking down between the plates and into the gap for the gear which will give the...

I just have read about a new kind hybrid diesel-steam engine where water has been injected inside an internal combustion engine to improve efficiency. The basic principle behind the process is that water will soak up a large section of heat generated by burning the fuel and will turn into steam...

Homework Statement [/B] I had an inorganic lab this week which involved making VO(acac)2 from VOSO4⋅xH2O. In order to calculate the percentage yield, I need to work out x, that is, the number of water molecules coordinated with the vanadyl sulfate n-hydrate before the reaction. I'm stuck...

Trying to calculate the power of a pump, it's pumping water. It has a flowrate in and out in kg/s. Surely I should look up the enthalpy values and just mutiply with the flow rate to get power in kW. However I know that if I convert flowrate to m3/s by dividing 1000 and multiplying by the...

As light travels through water, it's wavelength is shortened to compensate for the decrease in speed. This explains why there is little to no red light at depth. My question is: a) do these wavelengths eventually reach ultraviolet and beyond, for example at extreme depth are there only x rays...

Homework Statement A hollow stirrer that has a diameter of 2.0 mm is inserted into a cup of water at 20∘C. The surface tension of water at that temperature is γ(surface tension) = 7.28×10−2 N/m. What is the mass of the water supported by the surface tension in the stirrer? Given: d=2 mm...

In bernoulli's equation: when water is moving at a faster velocity, why is pressure decreased? I searched the forum and someone said that there is less water touching the surface? I do not conceptually see this. I understand for the lift factor with the example of blowing air over the...

Would shoes that vibrate very quickly enable us to walk on water? Why or why not?

a vessel in the shape of a cone is standing on its apex. water flows in at a steady rate, of 1m^3 per minute. the vessel has a height of 2m and a diameter of 2m when the vessel is 1/8 full find the rate at which water is rising v=1/3 pi r^2 h however i can't differentiate this

Hello, May I ask any civil engineers on this forum for their input of pros/cons of specializing in structural / water resources engineering? I am having a hard time choosing between the two because I really enjoy both subject. I enjoy both topics and I am afraid that if I choose one over the...

Homework Statement https://www.highlightskids.com/media/kids/highlightskids/images/thumbs/sciQuestions/sq1012_put-a-straw-in-a-glass-of-water_main.jpg Homework EquationsThe Attempt at a Solution From my understanding, this has to do with refraction. Here's my answer: ----- Light usually...

A person working in a company that manufactures absorption refrigerator told me that when Ammonia dissolves in water, the water temperature rises. In short, Ammonia absorption is water is exothermic. If it's true, then what's the reason behind it? Is it due to the fact that the latent heat of...

When we unfill a waterbottle, we here a periodic sound like- cloc.. cloc.. cloc..- How does this happen?

Not that I know of any hydronium pools, I was just wondering if there would be a difference in clarity or not (as in, harder to observe the bottom)

Hello everyone, First of all I am new here~ Second, I would like to "prove" on COMSOL that soundwaves (sound vibration) can alter/reshape the fluid flow Can someone tell me the physics i should use as well as all the other parameters to make it work? if someone is more experience can they...

I was cooking oats in water yesterday and the oats at the bottom of the pot got scorched. How is this possible? Doesn't the water smother the oats from oxygen?

Homework Statement A student looks at the sunlight reflected off a puddle of water. She puts a polarising (Polaroid) filter in front of her eye. As she rotates the filter the puddle appears darker then lighter. Explain this observation Homework EquationsThe Attempt at a Solution Here's my...

The Soviet Union constructed at two AMB series supercritical water reactors at Beloyarsk in the late 1950s, AMB-100 (Beloyarsk 1) and AMB-200 (Beloyarsk 2). They apparently achieved a mid-30% conversion efficiency, on par with more modern nuclear power stations and much better than the...

Homework Statement Calculate the vapor pressure of water at 25°C, based on the Gibbs free energy when vaporising from liquid water to vapor (so at 1 atm and 25°C ). Homework EquationsThe Attempt at a Solution After integrating d g/d p= RT/p. I get my formula p = p0*exp (-delta gm(p0, T)/RT). I...

We were measuring the amount of O2 dissolved in water by Winkler's method. Here's a link to the procedure and reactions: http://file:///C:/Users/SANJUKTA/Desktop/Downloads/Capture.PNG http://dropcanvas.com/6su7m/1 (The same is attached to this post) We had to use this formula: c(O2)...

I have a 1968 Mustang that I bought at auction from my grandfather's estate it is almost completely apart and I want to rebuild it for him has sadly he ran out of time, I have a reproduction manual from 1968 with frame dimensions in it and some of the dimensions car vertical to a datum line. I...

Hi All, Long time absentee from the forums hoping for some direction in my new research. I've been tasked to look into the stages of motion of objects (dropped from various heights), hitting a body of water (of various depths) and eventually hitting the seabed (of various sediment types). I am...

A person completely under sea water tracks the sun. Compared to an observer above water, which of the following observation would be made by the underwater observer? Neither the time of sunrise or sunset nor the angular span of the horizon changessunrise is delayed, sunset is advanced but no...

At swim practice last week I started thinking about how the composition of the water was affecting how fast my teammates and I were able to swim. The mechanical properties of the water--viscosity, density, surface tension, etc.-- are what determine how much force swimmers are able to generate by...

Which of the following statements about weak acids and weak bases are false? (i) The strength of a weak acid decreases as itspKa decreases. (ii) Weak bases react with water to produce a small amount of a strong base. (iii) The strength of a base decreases as the strength of its conjugate acid...

Homework Statement A big ice cube is placed in a small glass of water. The level of water in the glass is marked. When the ice cube melts completely,the overall water level will remain the same. Explain. Homework Equations Upthrust= weight of fluid displaced The Attempt at a Solution Since...

an idea for my new project construction - a cubical bowl of tap water , 2 sheet electrodes for 1 pair (y-axis pair)of opposite face(square wave 10Hz 10vpp), 2 sheet electrodes for the other pair (x-axis pair)(similar square wave lags by half cycle ) left hand touches adc pin. right hand touches...

Hi, a water tank will be put in the third level floor or slab. What must be the volume if gravity tank will be used so the pressure would be strong at 2nd floor and ground? It will be primarily a wet fire system. The tank won't be used for any other water applications since the building already...

Homework Statement Hi everybody. I am currently trinyg to solve the first exercice of the fifth chapter of R.R. Rogers book about cloud physics. "Show that the vapor pressure in equilibrium over a pure water drop of radius r decreases with T if r<2σ/LρL. Homework Equations...

Say we have a tire filled with air (equal to ambient air surrounding it in every way). pressure on the gauge is 0. Then, we pressurize it to 1 ATM (15psi). If we heat the tire , the air will be heated and expand based on gas law, or is there a factor that changes it based on the air's...

a bowl is filled with tap water .electric current is made to flow due to electrodes attached to rim of bowl(opposite sides of bowl) i have 2 sense pins inserted into the water between the electrodes . how can i convert this analog signal(vd across sense pins) to a digital signal to detect...

Homework Statement [/B] This is problem 10.27 in the Exercises for the Feynman Lectures on Physics, or Problem C-2 in Chapter 10 of Leighton and Vogt's Exercises in Introductory Physics. Homework Equations Using ##v_f^2 = v_i^2 + 2 a S## for the water in the vertical direction, we can find...

Consider pure water separated from an aqueous starch solution by a semipermeable membrane, which allows water to pass freely but not starch. After some time has elapsed, the concentration of starch solution a. will have increased b. will have decreased c. will not have changed d. might have...

Hello, I have a problem Basically, in theory -- a damaged 1220mm dia pipeline sub-sea (-8msw) with a 500mm hole in the 12oclock position 600mm. Pipeline resting on the seabed The goal of the problem is to flush the pipeline of its contents in both directions. The idea - have a containment...

Homework Statement A blacksmith drops a 0.7 kg horseshoe of iron at a temperature of 1200 ̊C into a bucket of 0.5 L of water at an initial temperature of 30 ̊C. How much of the water boils off? Assume the bucket absorbs none of the heat. Homework Equations I believe Q = mc delta(T) is what I'm...

I have heard that chilled water contains hard water. ie in the H2O contains another isotope of Hydrogen with a neutron. Is it true? If so, how it might affect our health if we drink?

Homework Statement [SIZE=13px][FONT=Helvetica Neue]Initially you have mW = 4.6 kg of water at TW = 74°C in an insulated container. You add ice at TI = -19°C to the container and the mix reaches a final, equilibrium temperature of Tf = 33°C. The specific heats of ice and water are cI = 2.10×103...

Hi, I am trying to create a device that would "simply" make a bubble under the water. What I am aiming for is production of small bubble but continuously and under the water. When I say continuously, it doeant have to be for extended periods of time, could be just for ~2 hours but the longer...

Hello All, I have a question for heat exchange calculation and hope someone can help. I would like to recover the "cooling energy" from a ice melting pool for air-conditioning for a small office. I plan to install three fan coil units with 800CFM for the office with closed loop water pipe to...

Hey everyone- I'm designing an ROV thruster which, for starters, will operate down to a depth of 300 feet. My problem is that I can't find any information regarding an electrical port which can pass through the hull out into the pressurized atmosphere without leaking. This will be a 12v system...

NASA report. ~10,000 cubic kilometers, more than even the most enthusiastic colony concepts could use in the whole 21st century, and even if we don't take recycling into account at all. The ground has 50-85% water ice, buried under a 1 to 10 meter surface layer of regolith - it should be easy...

I would like to recycle a source of used water at work. The water is contaminated with an acid solution and other chemicals used in a powdercoating process. My question is -- if I were to evaporate the water and then turn it back to condensate, would the water be pure? or would the acid and...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] So here's my question again, why do you need to include 40L of water in the total volume? It's not like AgCl is going to dissolve in water right? AgCl has low solubility in water. I mean if it was like NaCl then you should...

Hello - I am hoping for a bit of helping on a high school science project. I am looking for suggestions on how to force water through a tube or a screen within a barrel full of water as it rolls. I had a concept for using a UV light system to purify the water, but that option fell apart so I...

A closed, well-insulated container is filled with 454 g of water at 94.4 °C. To the hot water, 200 g of water ice at exactly 0 °C is added. The mixture reaches an equilibrium temperature of 41.1 °C. Assume the molar heat capacity is constant and all the processes are at constant pressure. The...

Is there a way to calculate the freezing and boiling point of water that has different levels of CO2 in it?

Homework Statement This was a test question I had today but basically, initially the mass is at rest as the buoyant force opposes the force of gravity. Then we push it down X meters and let it go. This can be described by SHM. We are also given the density of water, a cross sectional area of...

Calculate the area of water, suspended at 500m, needed to produce 23TWh of energy I've done a calculation but the answer seems far too small If I needed to store the UK's supply of energy for three months i.e. 23TWh of energy in a reverse pump hydro storage at an elevation of 500m using P=mgh...

ok i want to make 1g/sec of hydrogen out of an unlimited supply of water, i know the electrolysis won't start below 1.48 volts, let suppose i am supplying 2 volts of DC current, i need to find out the total wattage for electrolysis, for this i need the amount of current required to produce 1...