# Tag Info

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Ice cubes are colder than the water they are in, so the water freezes the two ice cubes together forming the bridge with the ice.

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It depends. Your elders probably meant an approximation in that the relative change is so small that you can neglect it for all practical purposes. I didn't do the calculation, but just make this back of the envelope calculation. The volume of the oceans is $1,335,000,000 km^3$ or about $1.3 10^{21} liters$. If you include one member of each species, the ...

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Um. This is an odd one, I think. It is simply not true that the amount of water in the ocean is always the same. In fact, the amount of water in the sea (well, also the volume of water--thermal expansion) has been increasingly lately and is forecast to increase in the future. It is true that there is SO MUCH water in the sea that we can remove a lot of it ...

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First up thanks to all who took an interest especially @irishphysics who stuck with the question for some time. It turns out that the phenomena was analysed and solved by Lord Kelvin and is known as the Kelvin wave pattern. The pattern itself is the result of a spreading pressure wave which manifests itself as the curved diverging wave crests (the ones I ...

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I will focus on just a little bit of one of your questions - the relationship between compressibility, density and pressure - and per my comment, recommend that you narrow down the scope of your question. As you know, in a gas we experience "pressure" because molecules hit the walls of the containing vessel. When I double the number of molecules in the same ...

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Well, it doesn't burn faster. I would say it burns slower but tans faster. Thats how dark tan oils work. The melanin absorbs the energy from the sun to charge and store it. The body wants more and produces more melanin. So you would get dark. However I believe the water on the skin just intensifies the energy, not the burning uv ray itself. Therefore, I ...

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Most likely what you are seeing is a thin film of oil floating on the surface of the water that comes either from natural underwater sources, runoff from the shore, or from ships. The oil breaks the surface tension of the water and reduces traction forces from the wind - thus ripple amplitudes are reduced or entirely diminished. This phenomena has been ...

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I've also seen this, and wondered what it is! I thought they may have been some sort of surface currents as they looked like "rivers" to me. However, I've just done some searching and found this and this. So the answer is biogenic slicks, oily substances exuded by algae washed off from the shore! These don't dissolve well with water and form a thin film over ...

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The effects are twofold. The first is similar to the damage caused by an explosion. The shock wave will travel through tissue without too much harm until there is a density discontinuity, for example flesh to air in the lungs. You then get a "Newtons Cradle" effect which causes mechanical damage to the lungs. The second possible cause of damage is tissue ...

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Raphael, Active SONAR emits pressure waves that bounce off of things in the water; the timing of the pressure wave bounced back is used to measure distance and develop images of what is underwater. Given that the energy in the pressure wave dissipates at a rate defined by the inverse of the square of the distance traveled (1/r^2), it obviously takes a ...

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Your post seems an awful lot like a homework question, so you should probably tag it as a homework-like question. If by "cup" you mean 250 mL on the dot, then we can say that the ratio of boiling water (100 Celsius) to room temperature water (22 Celsius) to achieve 80 degrees is $$\frac {(T_1)(V_1) + (T_2)(V_2)}{V_1 + V_2}$$ In your case, we have: $$... 0 From this link below " Refraction is the bending of waves because of varying water depths underneath. The part of a wave in shallow water moves slower than the part of a wave in deeper water. So when the depth under a wave crest varies along the crest, the wave bends. See "http://www.coastal.udel.edu/ngs/waves.html So my guess is its due ... 14 If you simply held a cup upside down in zero gravity, the liquid ought not to pour out. However, things in zero gravity still obey Newton's laws. If you pull away the cup, the water ought to stay behind. In reality, a sudden move of the cup would create a lower pressure behind the water than in front so the air pressure would try to keep it in the cup, but ... 3 Remember the laws of Newton. In this case the water will only accelerate with the forces you apply when tilting the cup. Assuming not fierce tilting of the cup: By the hydrogen interactions the water will therefore most like just float around shaped as one or more slightly deform bubbles in mid-air, or inside the cup depending on the "tilting forces". 10 Pour? No such thing without gravity. In NASA TV (see video), I saw the prototype coffee cups. They are shaped with a sharp crease, to allow liquid to ride up the groove. More advanced product would also mix waxy and wettable surfaces to keep it stuck to the inside of the cup but not crawl over the brim, except at the sip line. The pictures are hard to ... 0 This is simply the boiling of water, with the high rate of volumetric expansion producing a vibration in the air, thus producing sound. You can see that the sound is most evident when the nickel ball is in direct contact with the water, as the thermal conduction is greatest and thus water boils fastest when in direct contact. There is also a period of time ... 3 Keep in mind that the etched material is hydrophobic because of entrapped air in the etchings therefore, the water doesn't touch most of the surface. This means that when submersed, it will eventually loose it's hydrophobic properties as the air dissipates into the water. The submarine would also have the problem of increasing water pressure with depth ... 1 Displacement. Until the Vessel weighs more than the volume of water it is displacing it will remain afloat. Poke a very large hole in it.. Iceberg, torpedo or in the case of the Costa Concordia Sight seeing, it will most likely sink. Think of a Hydrogen filled balloon. It weighs less than the volume of air it is displacing so it rises.. Poke a hole in a ... -2 Due to abrupt transference of heat energy from hot oil to cold water drop. 2 Polyvinyl alcohol is the material used to make the water-soluble packing. The water molecule is polar (negative at one end and positive at the other). This nature of water allows it to pull the Polyvinyl alcohol molecules apart (which is usually how dissolving works). 2 It depends on what you mean by resonate. Water has three different vibrational modes - there are vibrational frequencies associated with these, but these are not really oscillations like a mass on a spring which we would be familiar with seeing. The webpage you link has some 'vibrational frequencies' of different molcules and notes they are significantly ... 0 In a static situation, the water would have a larger density when it has a larger pressure, so you could sink until you reach a level where the density matches. In reality, the water can have a different temperature and a different salinity (both of which affect density) and if can be flowing (up/down, east/west, north/south) and so it might never settle ... 0 Humidity does affect microwave propagation, but it is difficult to give a short review - microwave attenuation by water vapor depends not only on humidity, but also on the frequency - for example, water vapor has a resonance line in the microwave band - see some details in http://cdn.intechweb.org/pdfs/14248.pdf . 0 The force on the dam is the integral of the pressure over the area.$$F_{dam} = \int_{A}{p(z)dA}=\int_{0}^{Z}p(z)dz\int_{0}^{L}{dx}$$The pressure is a function of mass density, gravitational acceleration, and depth.$$p(z)=\rho g z Then the force on the dam is $F_{dam}=\frac{\rho g L Z^2}{2}$

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Since the pressure is dependent on depth, and your depth will vary if the structure (like a dam) is vertical, you will need to take the derivative of a vertical slice of the structure, and from there you will be able to multiply it by the horizontal (XY plane) area. your dx will be the change in depth making up for the "height" of the area for that ...

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Oil boils at a higher temperature than water which means that when water is poured into boiling oil it is heated to, and past, the boiling point very quickly. Oil is also less dense than water meaning that the water will sink to the bottom of the pot. Water at the bottom of the pot being heated very rapidly forms a gas at the bottom of the pot underneath ...

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