Specific Definition and 1000 Threads

Hello There, So I made a plot of some specific heats in refprop, and I chose the "Draw Saturation Lines" option. When I did this, the follow chart was produced. http://i.imgur.com/h34Pq.png Now my question is, what are these saturation lines representing? -TP

Homework Statement Consider the differential equation Find a general solution to this differential equation that has the form . . . y = Cx3 Find a second solution that might not be a general solution and which may have a different value of n than your first solution. The Attempt at a...

Homework Statement I need to find a specific chemical for a lab class. The manual states the chemical must: Be used as a drug in the pharmaceutical industry Have one chiral center Be soluble (make 4 Molar solutions) in water So...any ideas? Or, better yet, is there a database where I...

Homework Statement I am suppose to rearrange the integral in order to use this formula to solve it: ∫f'(x)/f(x)dx=ln|f(x)|+C Homework Equations My integral is ∫(e^x+1)/(e^x+e^-x+2). The Attempt at a Solution Any help?

Im sorry to ask such a question but I've been trying to understand the molecular reasons for why specific heat is high in some molecules but low in others. For example water has a specific heat of 4180 yet has a boiling point of 100 degrees Celsius but ethylene glycol (ethane 1,2 di-ol) has a...

Specific Heat: Bond or Freedom of Degree Based, Or Size?? Okay so I've been trying to understand what causes one substance to have a higher specific heat then other but I've read quite a few conflicting sources in which one says its due to the freedom of degree, while another says the weight of...

Homework Statement limit[1/(x-2)^3]=-inf as x->2 Homework Equations The Attempt at a Solution 2-delta<x<2 1/(x-2)^3 < M -delta<x-2<0 (x-2)^3>1/M (-delta)^3<(x-2)^3<0 =>(-delta)^3=1/M=>-delta=croot(1/M)=>delta=-croot(1/M) ...huh? how could delta be...

Homework Statement This isn't a specific problem ;) Homework Equations The Attempt at a Solution My thought process, skip to the last paragraph if you want the question: I was wondering how you compute an integral at a specific x value, let's say c. Based on the fact that the...

Short question: Does it matter if I do specific engineering or is engineering science just as good? Background info: I've taken two years of engineering science so far but they were all base level courses and haven't got too much into the real meat of engineering yet. I did just switch...

Recently, I did a physics lab experiment to find the specific heat capacity of an unknown sample material. The lab instructions kept insisting that the sample had to be kept in boiling water for at least 10 minutes. My question is why? Could I have found the specific heat capacity if the sample...

Could you please give me a hint on how to show that a set of operators with a property P is closed under addition? In other words, how one could prove that a sum of any two operators from the set still possesses this property P. The set is assumed to be infinite. Any references, comments...

Hi. I'm new here, first post. I hope I do it correctly :) I'm trying to solve a specific problem, which I need solved for a programming task. Now, my first approach was to iterate a solution which was close enough within some error boundaries I defined. But... it needs to be done correctly, if...

I was wondering how (or if it is known) the Higgs assigns different masses to different particles. We know that mass comes from the resistance that the Higgs field provides to particles but why are some particles such as photons able to move through without a hint of resistance, whereas...

Hi All I have a requirement where i want my motor pump to start at 6 AM morning and OFF after certain level of my water tank. I have browsed few links where i found some 555 timers and level controllers, but not able to consolidate them. Please help me the steps to assemble them in...

Homework Statement Have to do a write up of an experiment on specific heat capacity of metals. Tested 50g of nickel and lead, each heated to 90C and then put into 50g of water and measuring the change in its temperature. Found that lead has a lower specific heat capacity. Homework Equations...

[SIZE="3"][FONT="Times New Roman"]I'm doing a summer internship and my supervisor is currently away and uncontactable. He left me details of certain Hubble images to download and analyse asking for HST images of M31 with coordinates 00:42:52.534 +41:18:54.17 on 2006-07-15 and 2007-01-12...

Newton's Law of Cooling basically states (I believe): TObj = (TInital-TEnv)ekt + TEnv where k is a property of the material. In the equation: Q=mCΔT Specific heat capacity, C, is also a material property. So here's my question: Is there a relation between Newton's Law's k and the...

Below 20K, The specific heat capacity c of silver varies with temperature according to the equationc/\text{J /kg /K} = 1.5x10^{-4}(T/K)^3 + 6.0x10^{-3} T/K. If a small silver sphere of diameter 4am and at 20K is placed in 25g of liquid helium at 4K, what fraction of the liquid will evaporate...

Suppose you are given (1) a natural number N; (2) a set of natural num- bers S = {n1; n2; : : : }; (3) a set of arithmetic operators, say +; -;*; = (with the usual meaning of addition, multiplication, substraction, di- vision). Your job is to construct an arithmetic expression R built from...

Hi , I have a question that arose in mind. If gravity is a spacetime curvature just like GR says it is the I guess the only way to altering it is from the physical size/density of the object curving the space fabric, like sun being bigger having higher gravity and so on. But if we find that...

I work in a nano-optics group, and need an IR thermometer with certain specifications. Online I have only come across cooking thermometers and industrial thermometers, so I need help finding one for a physics experimental lab setup. Specifications: - high accuracy, and pin-point surface...

Homework Statement 0.2g of a radium salt was separated from a ton of uranium ore. The radioactive radium nuclide Ra-226 decays by alpha-particle emission with a half-life of 1600 years. 1 year = 3.16x107s. The curie is defined as the number of disintegrations per second from 1.0g of Ra...

In some work I have been following, I keep seeing notation like: for energy ... ML^2 T^{-2} How is this supposed to be read? I understand this is using mass, length and time, but what is it saying? Would I be right in thinking it says ''mass times length squared divided by time...

Homework Statement I have a tank that has 8000 cubic feet of helium in it. I have parts I'm filling to a gage pressure of 0.5 bar. The parts have a volume of 0.05ft^3. How many cubic feet of helium are in each part? Temperature is constant. Homework Equations I'm not sure if I'm missing...

Need help on Thermodynamics problem: thermal expansion to be more specific! A steel ring with a 2.5000in- inside diameter at 20.0°C is to be warmed and slipped over a brass shaft with a 2.5015in outside diameter at 20.0°C. Part A: To what temperature should the ring be warmed? Part B...

Homework Statement In this circuit E1 = 5.98 volts and E2 = 4.45 volts. To the nearest hundredth of an amp what is I1? I have attatched a picture Homework Equations V=IR 1/Req=1/R1+ 1/R2+ 1/R3 The Attempt at a Solution Well I think I know that resistance for the whole...

Homework Statement Give an example of a continuous function f:R^2→R having partial derivatives at (0,0) with f_1 (0,0)≠0,f_2 (0,0)≠0 But the vector (f_1 (0,0),f_2 (0,0)) does not point in the direction of maximal change, even though there is such a direction. (If this is too difficult...

Throughout my time doing physics I have noticed that ice has a lower specific heat capacity than water. I don't understand why. To me it seems that the bonds between water molecules in a solid are stronger and hence require a greater deal of thermal energy to break. Hence, the PE of the...

I just finished all of my finals today, and now the summer is here! I am in a REU for the semester, and I should have plenty of time to learn a programming language. So, this afternoon, I googled around a bit for information... and I can't figure out what to do! I was debating on Java...

Homework Statement A well lagged calorimeter of mass 120g contains 200g of water and 50g of ice, initial at 0°C. A jet of steam is blown through the water until the water temperature reaches 30°C. Calculate the mass of steam that must condensed. The specific heat capacity of Copper...

Homework Statement You are designing a two-string instrument with metal string 35.0 long, as shown in the figure . Both strings are under the same tension. String has a mass of 8.45 and produces the note middle C (frequency 262 ) in its fundamental mode. To extend the range of your...

I am doing a final year project. I have taken the wear rate of smaples (in mg). i know the load, sliding distance,COF, Frictional load. How do i find the specific wear rate?

It's not really homework its more of my own thing, but I don't know where else I'd put it Homework Statement category Main belt (Flora family) Orbital characteristics Epoch 6 March 2006 (JD 2453800.5) Aphelion 2.594 AU (388.102 Gm) Perihelion 1.825 AU (272.985 Gm) Semi-major axis 2.210 AU...

Homework Statement http://img577.imageshack.us/img577/2069/inertia.gif The following figure with these known lengths are given. I need to find the moment of inertia.Homework Equations According to my book's facit, this is the solution...

Homework Statement We draw 5 cards out of a normal deck of 52 cards. No replacements. How many combinations have exactly one Jack, one Queen, one King? Homework Equations The Attempt at a Solution The solution = 49,920 My attempts: I keep getting 99,840. So 4C1 Jack...

Hi, I currently have a degree in Microbiology and am considering going back to school this fall for either mechanical or electrical engineering. I am interested in aspects of both so I was wondering about the job outlook/chance of employment in a few specific areas of each. These areas are of...

I'm browsing through some acceptances posted by prospective graduate students here: http://www.physicsgre.com/viewtopic.php?f=3&t=4274 and there are some guys with very close to 4.0 GPAs and great GRE scores along with pretty good research experiences and letters of recommendations that are...

I'm using a PIC16F684.. Can someone help me write an assembly language program that switches on LEDs 0 to 7 in binary. There has to be a delay of 1 second between the change. Thanks,

In his Statistical Physics book, Landau introduces the specific heat as the quantity of heat which must be gained in order to raise the temperature of a body one by unit. I don't understand, how he directly jumps to the conclusion that that has to be (let's just say, for constant volume): C_V...

Homework Statement A 1-D lattice consists of a linear array of N particles (N>>1) interacting via spring-like nearest neighbor forces. The normal node frequencies are given by \omega_n=\omega_0\sqrt{\,\,2-2\cos\left(2\pi n/N\right)} where \omega_0 is a constant and n an integer ranging...

I have just done a lab on measuring the change in volume of an ethanol-water mixture. One of our tasks is to use the intercept method to determine the specific volumes of both the water and ethanol components at certain concentrations using a tangent line. I have the tangent line at 50%...

Hi there, I have a quick question. According to duLong and petit's law, the heat capacity at constant volume for most solids at high temperatures is 3R. (I.e) Cv=3R. Where R is the gas constant. Does this mean that the heat capacity is the same for all materials? I thought each material at a...

I completed high school 9 years ago... please bare with me :) My problem is with how they calculate the actual answer - this is from an example problem in my textbook. Homework Statement A calorimeter cup is made from 0.15kg of Alu and contains 0.20 kg of water. Initially the water and...

Homework Statement http://www.physics.ox.ac.uk/olympiad/Downloads/PastPapers/BPhO_PC_2006_QP.pdf Q15b Answers: http://www.physics.ox.ac.uk/olympiad/Downloads/PastPapers/BPhO_PC_2006_MS.pdf I am confused on how the answer is reached, specifically how the formula energy...

Is condensed matter physics the most useful field in physics to study for someone who wants to work in industry (with a B.Sc or M.Sc)? I am talking about in the USA for the record.

I have searched the mainstream books thomas calculus, steward and lots other like apostols,rudin etc. I was given two books in my college called analysis and applications but it is in greek written by an old local proffessor . It is 1600 pages total 2 volumes.. However the second book has...

I am looking for a fairly simplistic answer to why different "shells" in atoms can only hold a specific number of electrons. There is so much based on valence electrons and how many electrons make a full shell but, do we know why atoms "seek" a full outer shell? It seems like there should be a...

Homework Statement Find derivative of (x^2+1)^2*(x^3-2x)^2 Homework Equations This is globally a product and you would use the power rule as well as the product rule. The Attempt at a Solution [(x^2+1)^2*2(x^3-2x)*3x^2-2]+[(x^3-2x)^2*2(x^2+1)*2x] I believe I'm correct but...

I am quite confused by this, because I have not yet found a compound that has a higher one. My understanding is that specific heat capacity of a molecule is based on a combination of the number of degrees of freedom the molecule has and the number of vibrational modes. As for the second factor...

Three points are randomly chosen on a circle. Then they are connected together to make a triangle. What's the probability to see a 1. Right triangle 2. Triangle with all angles less than 90 degrees 3. Triangle with an angle bigger than 90 degrees I'm pretty sure to solve one of them...