is there a negative viscosity?
115618
I believe mercury has it.
95797
Like fLoWeRs said....you didn't give the equation! So I'm going to ansswer you based on what I regard as a standard exponential.\n\nf(x) = ae^bx + c\n\nThis is a fairly standard exponential as far as I know, and there's no reason why "b" can't be negative. In fact, if it weren't in some cases, we'd be living in a pretty funky place.
748261
if we assume that the following reaction occured\n\nA(l)----->A(g)\n\n[that means no A is not a polymer in liquid phase, the only thing occured  is the evaporation],\n\ntry plot ln(P) against 1/T, most likely you will have a straight line and the slope is - delta H/R, please notice the sign.
341402
Specific heat does not apply to reactions, only actual chemicals.  You are probably thinking of the heat of reaction, or enthalpy.  The change in enthalpy of a reaction (written as delta H, delta as the Greek letter that looks like a little triangle) flips its sign when the reaction is run in the reverse direction.  So a positive delta H value becomes negative when the reaction is run in reverse direction, and a negative delta H value becomes positive.
775873
So to say in simpler terms, every element has different properties and atomic reactivities which makes everyone change according to its own molecular activities in a given pressure. Each element got different boiling point as well as freezing point so you cannot assume that one certain element could behave the way others elements do. Negative temperatures surely means below the freezing point as far as water is concerned but Fluorine is far different from water, thus thinking that a negative temperature means freezing is totally not applicable to all the elements.♥
1166578
There is no such thing as negative matter.\n\nYou may be referring to 1 or 3 things:\n\nAnti-matter: Anti-matter is the "anti" particle to various particles. You have the antiproton, antineutron, positron, etc etc. They are basically particles with opposite charges but similiar other characteristics. \n\nExotic matter: Exotic matter is a hypthetical class of matter that violates current particle physics. Such matter hypothetically can have negative mass, have negative kinetic energies while in motion, or even be repelled by gravity. Some 'wormhole' theories rely on such particles.\n\nDark matter: Dark matter is matter of unknown properties that is being theorized to solve many problems associated with our current understanding of the universe. Such mass does not emit or re-absorb light.
428624
You need to be a bit more specific about which quantities you are trying to determine.  "Flow" is not a quantity to be calculated.
1127531
Surely you know the foumla for Re?\n\nRe=(density*velocity*length)/viscosity\n\nRe=(1000*1*25*10^-3)/1014*10^-3\n\nRe=24.655 (3dp)\n\nI think you've got yourself a laminar flow.
62373
No it is not possible to have a negative blood pressure. The book probably made an error. It would be impossible to have no blood which is what a negative means. A number less than zero. They were probably just seeing if you were going to change your answer to your problem. If you had it would have been wrong.
157984
lower viscosity in water (less of a resistence to flowing) therefore less rubbing between the particles in the fluid making it flow easier where as in syrup for example the particles are closer together and cause friction to make it flow slower. **a higher viscosity fluid (like syrup) is thicker than a lower viscosity fluid (like water)
249872
a. having both positive and negative end
211808
Visocity of fluid depends on---\n* Temprature--From everyday experience, it should be common knowledge that viscosity varies with temperature. Honey and syrups can be made to flow more readily when heated. Engine oil and hydraulic fluids thicken appreciably on cold days and significantly affect the performance of cars and other machinery during the winter months. In general, the viscosity of a simple liquid decreases with increasing temperature (and vice versa). As temperature increases, the average speed of the molecules in a liquid increases and the amount of time they spend "in contact" with their nearest neighbors decreases. Thus, as temperature increases, the average intermolecular forces decrease. The exact manner in which the two quantities vary is nonlinear and changes abruptly when the liquid changes phase.\n\n* Pressure--Viscosity is normally independent of pressure, but liquids under extreme pressure often experience an increase in viscosity. Since liquids are normally incompressible, an increase in pressure doesn't really bring the molecules significantly closer together. Simple models of molecular interactions won't work to explain this behavior and, to my knowledge, there is no generally accepted more complex model that does. The liquid phase is probably the least well understood of all the phases of matter.\n\n* material--Viscosity is first and foremost a function of material. The viscosity of water at 20 °C is 1.0020 millipascal seconds (which is conveniently close to one by coincidence alone). Most ordinary liquids have viscosities on the order of 1 to 1000 mPa·s, while gases have viscosities on the order of 1 to 10 µPa·s. Pastes, gels, emulsions, and other complex liquids are harder to summarize. Some fats like butter or margarine are so viscous that they seem more like soft solids than like flowing liquids. Molten glass is extremely viscous and approaches infinite viscosity as it solidifies. Since this process is not as well defined as true freezing, some believe (incorrectly) that glass may still flow even after it has completely cooled, but this is not the case. At ordinary temperatures, glasses are as solid as true solids.\n\n* Time--Some fluid viscisity are also affected by time like\n                            A thixotropic fluid undergoes a decrease in viscosity with time, while it is subjected to constant shearing.\n      This is essentially the opposite of thixotropic behavior, in that the fluid's viscosity increases with time as it is sheared at a constant rate.\n* Shear rate also affects fluid viscosity. Dilatant are examples.
722717
Your question is not very clear. Whether your talking about simple harmonic motion or not....x describes position. Velocity describes the rate at which the position is changing. And acceleration describes the rate at which velocity is changing. The short answer is that it's possible to have a negative velocity as well as a negative acceleration.
487540
Yes, there is. And the "best fitted line" has a positive slope. The graph is a scaterred dot becuase there are some other influencing factors. That makes love anf life more interesting.
875283
You differentiated and found it has relative min at x=1/3?  but if you differentiate again you find second deriv is\n54x - 1/(x^2), and I think this goes from \nnegative when x<1/cuberoot(54) to positive when it's greater, so that means it has an inflection.  Also means it's concave down when \nx<1/cuberoot(54), so the answer must be 5, not 2.  Unless I made a mistake!\n\nPS  Dave is wrong about 1.  Domain is all positive real numbers, because lnx is undefined for 0 and neg.
288909
well, acceleration is usually refernced as bing positive, therefore deacceleration, being the opposite of acceleration, should be negative.  but, however, if you say that something is deaccelerating at a rate of x units/time, then it should be positive.\nhope that helps!!
786580
Yes...\n\nB will be faster for n < 10^-Ω, afterwards A will always be faster.