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2

Here is a link to a study comparing heating water in a microwave to heating water in a conventional oven. Depending on the power of the microwave, the volume of the water, and time it's placed inside, the temperature will vary approximately linearly with time until either the system reaches equilibrium (for low power microwaves and large volumes of water) or ...


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I agree with Vladimir too. I tried both directions and both worked. I think that the shape of water basin may course. If it's true, there is a question. If water drain in different directions in Northern, Southern hemispheres which direction water drain in equator?


2

The coriolis acceleration is given by $a_c = -2 {\mathbf \omega} \times {\bf v}$, where $\omega$ is the angular velocity of the Earth and $v$ is the velocity of the water. The cross-product means that the largest this acceleration can be is $2\omega v$. If we assume the swirling water moves at maybe 0.1 m/s and $\omega = 2\pi/86400$ rad/s; then $a_c = 7 ...


0

I agree with Vladmimir, but want to add two more points 1) if you run water out and twist it one way with your hand it will run out that way, but then if you twist it the other way it flows out the other way - an experiment to try at home. 2) In the atmosphere the Coriolis effect does change the way air flows around a depression (region of low pressure) ...


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It is not true. I tried both directions and both worked. It depends, therefore, on the initial conditions.


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I don't believe that this would be necessary. Most pumps (not constant volume ones) have a relationship between flow rate and pressure jump (often called a pump curve). Since the entrance diameter of the pump doesn't change, you've got (basically) the same momentum in the pipe at a given flow rate regardless of how it gets that way. Another way of looking ...


0

Yes, the question is theoretical and so the response. Under enough pressure water will become a solid, regardless of temperature. That is, as far as it is still water. If pressure is high enough, the atoms will collapse and form neutron-degenerate matter (theorized to exist in the cores of neutron stars). I am not sure if there could be an intermediate mixed ...


1

In 1999, the president of the IEEE Power Engineering Society, Robert Dent, noted that: "The degree or intensity of the corona discharge and the resulting audible noise are affected by the condition of the air--that is, by humidity, air density, wind and water in the form of rain, drizzle and fog. Water increases the conductivity of the air and so ...


1

Shallow ponds will freeze all the way to the bottom (less than 5 feet), but deeper bodies of water will not. This is because the ice that forms on the surface insulates the water below. The temperature at the bottom of the lake is slightly above freezing. The ground is also just slightly above freezing. The water cannot be cooled down any lower since the ...


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Because the surface of the ocean cools faster than the bottom, in addition the bottom has greater preassure so it freezes at a lower temperature, comething that doesnt happenin a glass of water where the preassure difference is minimal. Plus there are subsurface hot currents, so the two systems are not equivalent at all.


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The thesis you refer to puts values of 0.02 S on the conductivity of freshwater and 4 S for seawater. I'm assuming that the S here stands for the SI unit of Siemens per metre, the value of $\sim 5$ Siemens per metre is one I have used for seawater in the past. Submarines communicate with frequencies as low as 100 Hz.To test for a "good conductor" we compare ...


0

Pascal used a serynge that allowed leakage of fluid, to demonstrate that increasing pressure at one point would increase pressure at all points. Although water is leaking, as Babou said, we can still consider the fluid enclosed, where, instead of holes (that allow leakage) we could use sensors to mesure pressure. Watch a Wolfram demonstration of the ...


1

An electromagnetic wave consists of an electric and magnetic field that moves through space. If the space that the wave moves through is filled with electric charges, such as the ions in salt water, then the electric field will start to push these charges around. This pushing requires energy, and this energy is drained from the electric field. This is the ...


3

This effect is called Capillary Action. Yes we do in fact observe it in nature in a large scale: How do you think plants are able to "suck up"1 water through its roots and send it to the leaves? One of the major forces responsible for it is capillary action. Here, have a quote from the article mentioned above: Wicking is the absorption of a liquid by a ...


3

As is given in Jamie's answer I'll assume the surface is a revolution about $r=0$, that the mean curvature is proportional to the pressure difference, and that the radius of the cup is much larger than the inverse of this mean curvature. In this case the mean curvature can be specified as $$ K_m = \frac{r''}{2(1+r'^2)^{\frac32}}$$ As in Jamie's answer the ...


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Waters recede before tsunami waves rush towards the land because of fault dipping or fault collapse (faults collapse due to underground system disturbances like oil extraction). Fault dip is characterized by downward movement of one fault wall resulting to its displacement. As faults gets displaced waters around the vicinity of the subsided fault will ...


2

You need a psychrometric chart. On the x-axis, input the value of a common air thermometer (it's the dry bulb temperature). Now follow a vertical line until you reach the red curve that reads 90% relative humidity. Follow the horizontal line to the y-axis on the right and that humidity ratio will be the ratio of water versus dry air (mass-wise). That is, ...


0

The question is unfortunately not very clearly stated; I cannot tell whether you (OP) were surprised about the fact that water is rising in the hole at all (as opposed to remaining at the level of the bottom of the ice), or about the fact that it rises all the way to the top of the ice (as the question states). By accepting an answer that explains that the ...


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I don't think John's explanation is sufficient. If 3 feet (90 cm) of ice is floating, it should leave about 7 cm of gap (according to the 92% number) - that is not what was described in the question, which was "the same level as the surface of the ice". But I think there is another explanation. Water level in bodies of natural water is subject to change, ...


5

It's because a bunch of people are standing around on the ice looking at the hole. You are floating ice with people and cars, not just plain ice.


60

Suppoose you put an ice cube into water, then it's going to float with about 92% of it underwater. This is shown in diagram (a) below: But now suppose I make my ice cube a different shape. I'm going to shape it like a disk with a hole cut out of the centre, or you could describe it as a flattened doughnut. When I put my oddly shaped ice cube into the ...


2

This question can't be answered from the picture alone without additional observations/data but @David Rose has given a good list of hypotheses. The size of the waves appear to be within the regime of 'capillary waves' Capillary waves are surface boundary waves with wavelengths on the order of millimeters up to a centimeter or two, where the energy restoring ...


0

(the same question was posted on Quora and this is a copy of my answer there. Most answers there really boil down to, "It's circular. Just look at it! You get circles! That's why it's circular.") I'd phrase it like this: The primary idea of most wave equations is that disturbances will only propagate at speed $c$. So we can look at the ideal propagated ...


1

The reason behind the hissing sound is that the temperature of the water droplet is much lower than the hot surface. As soon as the water droplet's base touches the hot surface it quickly evaporates but still the top part of the droplet is in liquid state and there is an opposition to th water-vapour coming from below. As the water-vapour couldn't vertically ...


4

The height of the puddle I will use the common definition of puddle in the field of capillarity (which I believe you refer to) which is: a droplet on a flat horizontal surface flattened substantially by gravity as shown in the schematic below, coming from the book by De Gennes (2003). The droplet on the left is just a droplet (with contact angle ...


0

According to Engineering Toolbox: the water vapor in air at 90°F and 70% RH is about 9.85 g per pound of dry air. The maximum amount of water vapor at 32°F is about 1.62 g per pound of dry air. So, depending on the air flow around your glass, it can condense a lot of water. Is it possible to reduce humidity of my room (10 feet × 10 feet ) in a ...


0

At 75% relative humidity and 90 F, there is abound 26 grams of water per cubic meter of air. If you had a sealed room 10 ft x 10 ft x 10 ft, at 90 F, reducing the humidity from 75% to 25% would require removing 615 grams of water vapor from the air, or 327 grams at 70 F.


0

The compression of a substance (liquid or solid) under pressure is described by the bulk modulus, $K$. The bulk modulus is a function of the compression, so the compression is given by a differential equation: $$ \frac{\text{d}V}{V} = -\frac{\text{d}P}{K} \tag{1} $$ In many cases we can approximate $K$ as constant, in which case equation (1) becomes: $$ ...



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