Properties Definition and 1000 Threads

Knowing: u * (v x w) = 5 where u, v and w are vectors. What is [Proj u (v x w)] * u Ive been staring at the dot and cross product properties in my book for a while and I don't see how to do it.

can anyone help me to find out the following air properties for higher temperature like 2550 kelvin? 1. Prandtl Number. 2. Raleigh Number. 3. Scattering coefficient. 4. Absorption coefficient. 5. Specific Heat. 6. Conductivity. 7. Thermal Diffusivity 8. Thermal expansion coefficient...

Thank you!

Homework Statement Let A be a matrix Then the following is true or false. (No need to explain why) a) rank(A) = rank(At) b) dim(Nul(A)) = dim(Nul(At) The Attempt at a Solution They are both true false right? The transpose swaps their row and columns which makes them...

Homework Statement Suppose that A and B are 5 x 5 matrices with the same Column Space (image). (a) Must they have the same columns? (b) Must they have the same rank? (c) Must they have kernels of the same dimension? (d) Must they have the same kernel? (e) If A is invertible, must B be...

Hi everyone, I'm trying to gather some ideas of subjects for an oral presentation in my Optical Properties of Materials class: I'd love to find something pleasant or at least nice to develop (like I heard "how a cameleon changes color?"^^), not too theoretical if possible... And with some...

Is there any properties with the curvature tensors in 3 dimensions? (Maybe between the Ricci tensor and the Ricci scalar, they are proportional to each other? ) I heard about it in a lecture, but I can not remember the details. The 3 dimensional case is not discussed in many reference books...

Homework Statement let \Gamma \subset C be the circle of radius 1 centred at 0. Let f: C \rightarrow C be an entire function such that for every z \in \Gamma f(z) = z Show that f(z) = z also on Int( \Gamma ) Homework Equations (f(z) - f(z0) )/(z - z0 ) = f'(z0) perhaps? The...

Alright so I know the common answer: Enantiomers - same chemical and physical properties Diastereomers - different chemical and physical properties In lecture, our professor said that enantiomers can have different biological effects. I was confused because, as he had said earlier, they have...

Homework Statement A slab made of unknown material is connected to a power supply as shown in the figure. There is a uniform magnetic field of 0.5 tesla pointing upward throughout this region (perpendicular to the horizontal slab). Two voltmeters are connected to the slab and read steady...

Urgent! Mechanical Properties at high temperature At first, My cordial respect to all members. I need help regarding my research study. I read a paper by Yaguchi, M., T. Ogata, and T. Sakai, Creep strength of high chromium steels welded parts under multiaxial stress conditions...

Can someone explain the difference between the two? 2 topo spaces are isometric if they have the same metric properties and homeometric if they have the same topological properties. If a space is homeo it is iso, but not vice verse. Which begs the conclusion that every topological...

Homework Statement this was a question in my book ... If the resultant force (external) acting on a body is 0, then from an inertial, one can surely say that (A) Linear momentum does not change with time (B) kinetic Energy does not change with time (C) Angular momentum does not change with...

Homework Statement Prove or disprove and salvage if possible: for [a], [b] ∈ Zn for a positive integer n, if [a]·[b]=[0], then either [a]=[0] or [b]=[0]. The Attempt at a Solution I've managed to disprove the statement: Let n=6,[a]=3,and[b]=[4]. The[a]·[b]=[ab]=[3·4]=[12]...

hello I have a question about the periodicity of complex exponential in discrete time and continuous time in continuous time we have x(t) = e^(j*ω*t) while in discrete time we have x[n] = e^j(ω*n) for the first in order to show whether its periodic we say x(t+T) = x(t) => ...=> T =...

There are certain properties of materials that are "artificial" in the sense that they have no direct physical basis but are sort of added into the evolution equations to get the right effect. I don't mean to sound like they are arbitrary but that they are more empirical and not directly...

Homework Statement If s is a ring with the property that s=s^{2} for each s\in S, which of the following must be true? I. s + s = 0 for each s in S. II. (s+t)^{2}=s^{2}+t^{2} for each s,t in S. III. S is commutative Homework Equations none The Attempt at a Solution The answer is I, II...

Homework Statement Hi. I need to prove (or at least make a conjecture) about the infinitude of primes in these cases. 1) N^2+2 2) N^2-2 3) N^2+2N+2 4) N^2+3N+2 Homework Equations none? The Attempt at a Solution Already solved for number 4. This is always even, therefore there is not an...

how we look in for particles,decide their properties like mass ,charge,spin etc in experiments(collision experiments)?

I was reading all over the place that graphene has some really great electronic properties that could potentially replace silicon, electrons in graphene behave almost like massless particles etc. My question is, HOW did scientists find out these properties in graphene? What kind of experiments...

Warning: I'm not a practicing chemist. Answers in as-simple-as-possible language (but not oversimplified!) would be greatly appreciated! I'd like to know if the chemical properties of a solid can be affected by conduction band electrons. I assume that, in the majority of cases (and perhaps...

Dear all, a homomorphism is a continuous 1-1 function between two topological spaces, that is invertible with continuous inverse. My question is as follows. Let's take the topologies of two topological spaces. Is there a 1-1 function between the two collections of open sets defining the...

I'm working on a computer model that simulates material damage in fiber reinforced polymers in extreme temperatures. I have looked around to find where I can buy some and get material properties. So far the best place I have found is Rock West Company with their quasi-isotropic lay...

Trying to show any f(z)=u(x,y) + i*v(x,y) with the 3 properties: 1. f(x+0*i)=e^x, 2. f(z) is entire, 3. f ' (z)=f(z) for all z, has to be f(z)=(e^x) * (cos y + i*siny). The hint in the book (Complex Variables and Applications, 6 ed., Churchill+Brown) says: (a) Get u=u sub x and v=v sub...

Hey all, I'm looking for a version of steam/water thermodynamic properties for excel. I need it to be able to compute properties based on pressure and entropy. Something similar to the X Steam Tables (http://www.x-eng.com/XSteam_Excel.htm) would be awesome, but again, I need the ability to...

Properties of matter... Homework Statement A 5m long cylindrical steel wire with radius 2*10-3 m is suspended vertically from a rigid support and carries a bob of mass 100 kg at the other end...If the bob gets snapped calculate the change in temperature of the wire ignoring radiation...

Hi, I would like to apologize in advance if I violate any forum rules. I am interested in physics just for general knowledge, I have sometimes a few weird questions that I have no way to find an answer by myself. I hope you can help. Here is the question. Water is quite convenient as a...

1) If det(AB) = 0, is det(A) or det(B) = 0? Give reasons for your answer. Q1) First, cannot both det(A) or det(B) be 0? If it can, is this statement false. In any case, how can I prove that this is true for all statement since I only know how to find an example to show this is true, which...

Homework Statement (This is an example of a group in my text). An integer 'a' has a multiplicative inverse modulo n iff 'a' and 'n' are relatively prime. So for each n > 1, we define U(n) to be the set of all positive integers less than 'n' and relatively prime to 'n'. Then U(n) is a group...

What are similiarities between ether and alcohol and how can we use at least 2 physical properties to differentiate between them? For ex, alcohol has a higher boiling point, so what "procedure" would I follow to test the boiling points to find out which is which.

Homework Statement I am so close to this breakthrough I can taste it. I say this because I haven't taken a shower in four days. Anyways go to this link http://physics.bu.edu/~duffy/py106/Electricfield.html My questions 1) This part. OKay so a conductor is charged, all the excess...

Homework Statement A volume of 2.40x10^-3 m^3 of hydrogen gas is enclosed in a cylinder with a movable piston at 300 K under a pressure of 203 kPa (2.00 atm). The density of hydrogen under these conditions is 0.180 kg m^3. 1. The gas is cooled down to 150 K, and the pressure is increased to...

Homework Statement Prove that |X+Y|^2 - |X-Y|^2 = 4X(dot)Y using general properties of vectors. Homework Equations ? The Attempt at a Solution I'm very confused about how to start this. If someone could give me some help to just get me started then that would hopefully get...

I was wondering, since vacuum energy is supposed to have some energy density,according to standard comology equating it to dark energy and cosmological constant , does this energy gravitate? I mean it looks like according to GR its stress-energy tensor with negative pressure should generate some...

A scientist notices that an oil slick floating on water when viewed from above has many different rainbow colors reflecting off the surface. She aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). The index of refraction of water is 1.33 Now assume that...

Hey guys, I'm having some trouble finding thermodynamic tables for n-pentane and n-butane. Does anybody know where I can find them, whether it be in books or (a trust able) online source? Thanks.

According to special relativity, Would a tachyon's time be imaginary? I saw somewhere that they move backwards in time... Also what would it's length be?

What are the properties of anti-matter? Does anti-matter have anti-mass? Since there is anti-matter, is there also anti-energy? Is anti-matter subject to anti-gravity? Can particles with no anti- counterpart be considered as matter?

Sodium is a soft, reactive metal. Chlorine is a poisionous, reactive gas. Expose them to one another and they will form table salt, through ionic bonding. The compound is bonded throughout, forming a geometric matrix of bonds. If submerged in water, it will be dissolved into free Na+ and...

I was just curious as to how I can show the following properties of the Gamma Function, they came up in some lecture notes but were just stated? Notation: G(z) = Gamma function 2^(z) = 2 to the power of z I = Integral from 0 to infinity (1) G(z)*G(1-z) =...

1) If A = [aij] is an n x n matrix, the trace of A, Tr(A), is defined as the sum of all elements on the main diagonal of A, Tr(A) = the sum of (aii) from i=1 to n. Show each of the following: a) Tr(cA) = cTr(A), where c is a real number b) Tr(A+B) = Tr(A) + Tr(B) c) Tr(A(Transpose)) = Tr(A)...

Apparently, strained nanocrystals of PbTe are able to achieve a high thermoelectric figure of merit, for improved thermoelectric conversion efficiency: http://www.eurekalert.org/pub_releases/2011-01/nu-bic011811.php http://www.nature.com/nchem/journal/v3/n2/abs/nchem.955.html So if...

Homework Statement Let f be a differentiable function, defined for all real numbers x, with the following properties: 1. f'(x) = ax^2 + bx 2. f'(1) = 6 and f"(1) = 18 3. \int_{1}^{2} f(x)dx = 18 Find f(x). Homework Equations The Attempt at a Solution Using the first two properties, I...

Im working on test corrections that are due tomorrow, and I was out sick for around a month and a half or so. I have been trying to find these in our book, however, our book is pretty much a big hunk of annoying weight that should be used for a campfire. Anyway, I am looking for some help with...

1. Prove that an ordered field has the LUB property iff it has the GLB property. I know that I need to prove that if the ordered field has the GLB property, then it has the LUB property, and that if the ordered field does NOT has the GLB property, then it also does not have the LUB...

How can I explain that the fact that a covariant second rank tensor is symmetric in one coordinate system is a tensorial property. This is for my GR course, but I didn't do a Tensor Calculus before.

Hi all. I hope to have a better understanding of the consequence of introducing high heat on water in a hot water pressure washer. I know that hot water cleans better than cold or warm, and steam even cleans better. But am I harnessing the additional heat energy applied to the water in the...

I have a powerpoint presentation and I don't really understand this topic . I have looked up for vacuum and dielectric materials individually and separately but still there is no success. I found one website very useful but I am not sure is this a same thing. Please help ...

Suppose the function f has the following four properties: 1. f is continuous for x >=0; 2. f'(x) exists for x > 0; 3. f(0) = 0; 4. f'is monotonically increasing. I'm just looking for functions that have these 4 properties to better understand what f represents. So far, I came...

Mass, Charge, Spin has definite properties before measurement. What else aside from position, momentum that have NO definite properties before measurement. Is it only position and momentum?