Specific Definition and 1000 Threads

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...

Assuming we have a closed loop system (A-BK), with stable eigenvalues, how would one choose matrices Q and R such that the eigenvalues of (A-BK) are exactly [-1,-2]? LTI System: \dot{x}=\left[ \begin{array}{cc} 0& 1 \\ 0 & 0 \\ \end{array} \right]x+\left[ \begin{array}{c} 0 \\ 1 \\...

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...

1. Homework Statement Consider air inside a piston-cylinder device that is compressed adiabatically from p1 = 100kPa, T1 = 300 K, and V1 = 0.5 m^3 to V2 = 0.03 m^3 and then heated at constant pressure until T3 = 2000 K. The heat is exchanged with a heat reservoir at TH = 2000 K. Determine P2...

Homework Statement Consider air inside a piston-cylinder device that is compressed adiabatically from p1 = 100kPa, T1 = 300 K, and V1 = 0.5 m^3 to V2 = 0.03 m^3 and then heated at constant pressure until T3 = 2000 K. The heat is exchanged with a heat reservoir at TH = 2000 K. Determine P2...

I am again confused at this. As far as I know, specific speed of a turbine of given Shape and Size is defined as -"The speed at which geometrically similar (i.e. scaled down Version) turbine would rotate when provided with unit head and unit discharge" The general text-book derivation for...

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...

Does the value of specific heat change with phase? If yes, why so and what are its values for Al in liquid and solid phase.

I was reading an article on Pseudomonas syringae and how removing a gene called inaZ from it's DNA will allow it to be sprayed on crops to prevent the crops from freezing during the winter. How is the inaZ gene removed from the DNA? I'm thinking that they use restriction enzymes that cut out the...

Homework Statement A saucepan of thermal capacity 500J/degC contains 5kg water at 20 degrees celcius. How much energy is required to raise the temperature of the saucepan and water: a) to 60 degrees b) by 60 degreesHomework Equations Q = mcΔt mcΔt = mcΔt The Attempt at a Solution First I just...

What does the author mean here when he says How does a massive particle have a specific chirality? I learned that the only massive single chiral fields are the ones with Majorana mass. Dirac fields are a mix of left-chiral and right chiral fields, they do not have a specific chirality. Is...

Hey guys. I need help figuring out how to do this problem. I have a test tomorrow and i am currently studying. I would like to know how they got this answer. I'm completely stumped and need help so thanks in advance! Here is the question: http://img405.imageshack.us/img405/624/physicsv.jpg...

Homework Statement Consider phonons propagating on a one-dimensional chain of N identical atoms of mass M interacting by nearest-neighoour spring constants of magnitude C. a) Show that the Debye frequency can be written as \omega_{D}=\pi(C/M)^{1/2}. b) Show that when the temperature is...

Homework Statement Calculate the change in the enthalpy of argon, in KJ/kg, when it is cooled from 100 to 25 °C. Homework Equations \Delta h = c_{p} \Delta T Where \Delta h is the change in enthalpy, c_{p} is the specific heat, and \Delta T is the change in temperature. The Attempt at a...

Homework Statement A block of mass 'm' is placed on an inclined plane which has an adjustable angle with the horizontal. The angle is increased slowly from zero until the block just starts to slide. This angle is called the critical angle, θs. Express the coefficient of friction in terms...

A bath contains 100kg of water at 60C. Hot and cold taps are then turned on to deliver 20kg per minute each at temperatures of 70C and 10C respectively. How long will it be before the temperature in the bath has dropped to 45C? Assume complete mixing of the water and ignore heat losses. I've...

Homework Statement Right now I'm doing a bit of self learning on the topic of synesthesia. It is a condition in which a person makes strange and automatic associations between seemingly unrelated concepts. For example some people always see numbers in colour and some always see letters in...

Homework Statement A cube of gold is heated to a temperature of 94.2 degrees celsius, and then submerged in 31.3 mL of water at an initial temperature of 28.7 degrees celsius. If the final temperature of the water is 45.6 degrees celsius, calculate the volume of the cube of gold (s=0.130...

Homework Statement A parcel of dry air is lifted isothermally such that its pressure decreases from 1000 hPa to 850 hPa. Calculate the change in specific entropy of the parcel. Homework Equations ΔS=n*R*ln(p1/p2) The Attempt at a Solution Using R=8.314 J/mol K p1=1000hPa...

Homework Statement there is a bath of 160L of water at 41oc (shc 4000). A rock of 15kg is dropped into the bath at 250oc with shc of 2000 What temperature does the water end up at? Homework Equations Q=cmT The Attempt at a Solution Very sorry but I don't have a clue. Not...

Homework Statement Estimate the precise value for the specific heat of a nitrogen molecule at T=13.6K Homework Equations I'm pretty sure the correct equation is: Cp = (7/2)*R + R((hv)/(kT))2 *((e(hv/kT))/(e(hv/kT)-1)2 So R=8.314 J K-1mol-1 T=13.6K h=6.626*10-34m2kg s-1...

Hello everybody, I have a shape (polygon) made up from pixels (squares) similar to the image below. I need an algorithm to cut it into "lines" i.e. shapes of 1x[1..20] pixels. The lines should not be necessarily straight, but they should fill the entire area. Any ideas on where to start...

Homework Statement Electrons in crossed electric + magnetic fields: Simulation. I need to find e/m with known E, U and B. Easy way to find e/m is to set U, E and B such that I don't get any deflection of the electron beam. In that situation magnetic and electric force are equal -> E=B*v...

Hello everyone, as the title suggests I'm in need of finding some specific vendors or catalogs for a few particular items needed in my design project. My University will be taking care of the bill, so while I would appreciate modest cost expenses, it would benefit my college to have some of...

I was going to post this on Earth-forum here but I thought that you guys here can help me better with this. I'm trying to get the radius of Earth on every latitude degree from 0° to 90°, knowing 0° at Equator is ~6378,137km and 90° at North/South Pole is ~6356,7523km (source Wikipedia). In...

Homework Statement To determine the Specific heat of an oil , an electrical heating coil is placed in a calorimeter with 380g of the oil at 10C. The coil consumes energy(and gives off heat) at the rate of 84W. After 3min the oil temperature is 40C. If the water equivalent of the calorimeter...

Homework Statement A 1m^3 container is filled with the following -).12 m^3 of Diamonds -).15 m^3 of sand -).2 m^3 of petroleum at 20 deg Celcius -).53 m^3 of air 2 20 deg celcius and 1 atm pressure Find overall specific volume and density of container Homework Equations...

Homework Statement See attachment "problem". Homework Equations See attachment "data" The Attempt at a Solution Can someone tell me what values to plug in for the equation R/M integral (a+bT+cT^2...). The solution doesn't show this step, so I have no idea the numbers they used to...

1. What is the value of Q in this problem? Is it a value that's stated in the question or does it need calculating? A sample consisting of 5 moles of an ideal gas at a temperature of 300 K and a pressure of 1.00 × 105 Pa is heated to a temperature of 500 K at constant pressure. The amount...

Homework Statement Part a. A 500 W kettle contains 300g of water at 20°C. Calculate the time it would take to raise the temperature of the water to boiling point. Part b. The kettle is allowed to boil for 2 minutes. Calculate the mass of water that would remain in the kettle. State any...

What is the the relationship between the specific heat capacity and power (e/t) required to raise the objects temperature? Of course the energy required increases, but does the time it takes change also?