Specific Definition and 1000 Threads

Homework Statement Here g(ε_f) is the density of levels at the Fermi energy and T is the temperature. Calculate the specific heat of the electron gas in potassium (K) treating it as a free gas. For a free gas the density of electrons at ε_f is: g(ε_f)=(3/2)(n/E_f) where n is the electron...

Hi boys and girls. I am looking for Specific heat capacity of Argon dependence on temperature but i can't seem to find it anywhere. Do you have some source where I could get it from?. I need it for temperatures up to 1300K since i need to evaluate enthalpy of fumes at the exit from a gas...

Hi everyone, I am trying to solve the following problem. Is there exist a transformation matrix T, different then the block diagonal, with all blocks the same, such that the form of the matrix A=[A1 A2 ; I 0], is preserved? All blocks of A are in R^{nxn}, I is identity and 0 is zero matrix. In...

Hi, I'm trying to create a normal distribution with mean 0.5 and variance 0.05. I tried it initially with MATLAB, for which I used newdist=0.5+(randn(1,1000)*sqrt(0.05)); Could you please help me in doing this in FORTRAN 90? Would generating a sequence using RANDOM_NUMBER and using the...

Nice little paper about properly validating your reagents: http://www.ncbi.nlm.nih.gov/pubmed/22361696Why is it in academia absolutely no one validates their reagents like antibodies while in industry it is absolutely required? Rather than admitting their results are due to nonspecific...

Why is the specific heat capacity of most solids around 25JK-1mol-1? I remember being told ages ago that is was something to do with the theory of equipartition but I'm not really sure how that theory affects it or why it's around 25JK-1mol-1

In my previous PDE class we did nothing with method of chars. Now I am assigned one in a higher class, but all the examples I find online are not helpful for a particular problem I have. du/dt+a*du/dx=f(t,x) with u(0,x)=0 and f(t,x)=1 if -1<=x<=1, and f(t,x)= 0 otherwise Differences...

Homework Statement How fast must a satellite 10,000 miles above Earth's surface travel, and how long does it take to complete one orbit of Earth? Homework Equations v^2 = g*r The Attempt at a Solution 10,000 miles + radius of Earth = 14,000mi = v^2 = (9.8)(2.253*10^7m)...

Can someone please tell me what does the symbol H and what does the symbol U represent in these equations: http://www.taftan.com/thermodynamics/CP.HTM"][/PLAIN] http://www.taftan.com/thermodynamics/CP.HTM

Homework Statement http://img687.imageshack.us/img687/8767/meprob27.jpg If the resultant force acts along the positive u axis, determine the resultant force and angle theta (red angle) Homework Equations law of sines pythagorean theorem, etc trig parallelogram, head to tail methods...

Homework Statement I have some boiling water that I am adding potatoes to. I am asked to find the final temp after the potatoes have been added to the boiling water. Tiw=100C (initial boiling water temp) Tip=30C (initial room temp potatoes) mp=0.5kg (mass of potatoes) mw=1.5L or 1.5kg (mass...

1. Suppose that 25 J of heat is added to one mole of an ideal gas. The gas expands at a constant pressure of 2.62 x 10^4 pascals while changing its volume rom 4.97 x 10^-4 m^3 to 7.02 x 10^-4 m^3. Calculate C_p and express in Joule / (mole * Celsius) 2. Relevant equations Q =...

Homework Statement So a chart is given. | | Water vapor at p (pressure)=0.006MPa | Water vapor at p (pressure)=0.035 | T(in degree C) | v(m^3/kg) | v(m^3/kg) | 80 | 27.132...

I've run the experiment. By varying the current and fix the mass of the electrode, I found out that the specific capacitance (Csp) is increased when applied current (I) is increased. By using this formula, Csp = 4I / [M*(dV/dt)], where I is the applied current, M is the mass of both...

Homework Statement Suppose molten (liquid) lead, mass ml = 9.83 kg, is at its melting point. The lead is poured into water of mass mw = 585 g and initial temperature Tw = 16.2 C. Find mwb, the amount of the water that boils. NOTE: Reaching the boiling point is not enough; the question asks...

Homework Statement A 4m wide channel has a bed slope of 1 in 1500 and a Manning's roughness coef n=0.01. A broad crested measuring weir in the form of a streamlined hump 0.4m high spans across the full width of the channel. the discharge is 10.5m^3/s. Determine i)the uniform depth of flow...

Homework Statement The switch in the RC circuit shown in the figure is closed at t=0. What is the charge on the capacitor at the time t = .35 ms? I'm 95% sure I'm using the right formula but it's not working so I was wondering if I was possibly confusing something? Homework...

Homework Statement What is the specific gravity of a mixture 40% ethyl alcohol and 60% water? The specific gravity of ethyl alcohol is 0.79.Homework Equations The Attempt at a Solution He showed us a way to do it for another type of problem but I approached it a bit differently and I wanted to...

1. Hi, basically I'm trying to find an equation to find ion specific molar conductivity of salt water flowing between electrodes. Homework Equations resistivity: rho = RA/L conductivity: kappa = 1/rho conducitivity per unit concentration: lambda = conductivity/concentration this is ion...

Homework Statement Find f if f"(x)=12x2+2 for which the slope of the tangent line to its graph at (1,1) is 3.Homework Equations The Attempt at a Solution What I did first was found f(x)=x4+x2+cx+d (cx and d being constants of integration.) and from this point I attempted solving for cx and d...

When I integrate v(t) after I calculated the t, what do I get? Let;s say t=2. do I get the position vector in this 2s? If so it means the integral goes from 0 to t? or I still need to calculate from 2 to t? I could simply integrate v from 0 to t then place 2 in the position vector but I got an...

Homework Statement Let 25.6 J of heat be added to a particular ideal gas. As a result, its volume changes from 41.0 to 82.0 cm3 while the pressure remains constant at 1 atm(= 101 kPa). a) By how much did the internal energy of the gas change? -- 21.5 J got this part b) What is the molar...

1. Use equation for the magnetic vector potential in the case of specific current distribution and show by direct differentiation that ∇\bulletA=0 A(r)= µ_{0}/4\pi \int J(r')/|r-r'| dv' Homework Equations ∇\times B(r)= µ0J(r) The Attempt at a Solution We know that: curl of...

Dear all, As we know, there are two kind of capacitor polar and non polar. From that, I still did not know yet about specific application of them. Can give me something a clear of explanation of that? thank you reza_diharja

Homework Statement Hi. I have an assignment to find the specific heat capacity of water. We did an experiment in class where we used an electric kettle with power output of 1850W-2200W to heat up 1,400g of water (we actually used 1,400 mL of tap water but we were told to assume that the tap...

Homework Statement We completed a lab with the following information Substance Mass(g) Starting temperature (°C) Final Temperature (°C) Ice cube 15.55 0 12 Water 151.25 21 12 Now...

Homework Statement At very low temperatures, the molar specific heat of many substances varies as the cube of the absolute temperature: C=k*(T^3/To^3), which is sometimes called Debye's law. For rock salt, To= 281K and k= 1940 J/mol*K Determine the heat needed to raise 2.40 mol of salt from...

Homework Statement What is the heat capacity of water in J*g*°C Homework EquationsA 74.8 sample of copper at 143.2g is added to an insulated vessel containing 165ml of water, Density of water = 1.00 at 25.0 °C. The final temperature is 29.7° C The specific heat of copper is 0.385 J*g*°C...

Homework Statement A 500.0-g chunk of unknown metal, which has been in boiling water for several minutes, is quickly dropped into an insulating Styrofoam beaker containing 1.00 kg of water at room temperature (20.0 C). After waiting and stirring for 5.00 minutes, you observe that the water's...

Metals have the low specific heat capacity.why is the low specific heat capacity useful?

Can we define specific heat capacity for an adiabatic process ?? Would it always be zero since dQ is 0 for an adiabatic process? Also, can we define specific heat capacity for isothermal processes ? Would it be infinity in all cases? Just want to verify if I am thinking along the...

A liquid contained in an adiabatic container is shaked vigorously so that it its temp. Increases. The heat capacity for the liquid is given, the rise in temp. Is given. According to the first law of thermo, dQ=dW + dU here dQ is 0. Asked, is to find the work done on the system, i.e...

I am trying to solve a question which gives me the volume of a mixture and its specific gravity and the percentage of one of the substances in that mixture by mass(everything else in the mixture is irrelevant). I need to find the mass of that substance but I can't seem to understand what I am...

Hello, I am working on a project that involves using 2D triangles to build 3D models and I am looking for software that will allow me to draw 2D triangles based on the triangles 3 edge lengths (ex: 4 cm x 5 cm x 3 cm). Most of the software I have found requires knowing either the triangles...

Are P-elements a specific transposon or are they just inverted repeats (IR's)?

Hi! I have worked on this for a while and cannot seem to get a reasonable answer. I have been given the Luminosities of planets at different wavelengths and I need to determine the Temperature. I re-arranged Planck's equation to find T but I keep getting really low temperatures Planet A...

Homework Statement A beam (note: part of a truss, I chose to use the beam in the truss with the most force and length for my calculations, which I assume is the correct thing to do) of length 6m with a force of 9N is being constructed out of a material with a Young's Modulus of E = 70 \times...

I found an example like the problem asks, but I'm still trying to show the first part. You want the maximum number of subsets such that you can guarantee none are pairwise disjoint. I'm trying to apply my specific case to the whole problem. For a set with 3 elements, I chose all of the sets...

Homework Statement I was wondering, how can i measure the specific heat capacity of a solution? Not the exercise, just doing an experimental work to measure it. Homework Equations q=mct The Attempt at a Solution I'm lost.

Homework Statement Develop the mesh-current matrix equation for the circuit. http://i.imgur.com/tvZA0.png Homework Equations ƩV_{n} = 0 The Attempt at a Solution I used Mesh current analysis to find 4 equations, but the equations for the first and second mesh are not related...

I've been working at this problem for a while and it seems that there should be an easier more systematic way of solving it. Here it is: Find a proposition using only p, q, ¬ and the connective ∧ with the given truth table. p q ? T T F T F F F T T F F T I know of a...

Homework Statement i getting the wrong the answer i am trying to find the specific heat capacity of brass using copper calorimeter Data : mass of brass bob= 32.5gm mass of calorimeter = 39.7 gm mass of water + calorimeter = 93.9gm mass of water = 93.9 - 39.7 = 54.2g specific...

Homework Statement A fish is swimming in a horizontal place has velocity of ( vi = 4.00i + 1.00j) ms at a point in the ocean where the position relative to a certain rock is ri=(10.i- 4.00j)m. After the fish swims with constant acceleration for 20 s, it velocity is v = 20.0i -5.00j. Question...

Homework Statement A 2.8 kg sample of a metal with a specific heat of 0.43KJ/KgC is heated to 100.0C then placed in a 50.0 g sample of water at 30.0C.* What is the final temperature of the metal and the water? Homework Equations heat loss by the metal = heat gain by the water The...

Homework Statement A sample of hydrogen is at a pressure of 1000mb and a temperature of +10° C. Calculate its specific volume.Homework Equations I'm guessing PV=mRT The Attempt at a Solution P=1 bar m=2 g R=constant (do I use the universal constant or is there a constant for Hydrogen? If so...

C_{V} = \frac{∂U}{∂T} This is the specific heat at constant volume so I assume it can only be used at constant volume. However, my textbook uses this to derive the following equation for reversible adiabatic expansion: P_{1}V_{1}^{γ} = P_{2}V_{2}^{γ} Why are we allowed to use C_{V}...

Homework Statement Some aluminum rivets of total mass 170 g at 100°C are emptied into a hole in a large block of ice at 0°C' a. What will be the final temperature of the rivets? b. How much ice will melt? Homework Equations none The Attempt at a Solution Please help me answer...

what is the relation between Specific Heat and Absolute Temperature of any material ? Specifically, Sodium. Cp vs T ( not the change in temperature) Any mathematical formula ? Thanks

I'm working on writing my graduate school application right now. It was easy to talk about my academic qualifications and all the research I have done. But I don't know how specific I need to get when talking about what I'm interested in. I'm a chemistry major. I have a broad interest in...

I got a problem with this one, please help me, Tantalum is an element that is used in aircraft parts. Tantalum has a specific heat capacity of about 140 J/kg K. The aircraft part has a mass of 0.23 kg and is cooled from a temperature of 1200 K by being placed in water. If 30000 J of heat is...