Calculations Definition and 982 Threads

Homework Statement a particular nuclear power reactor operates at 1000MWe (megawatts electric) with an overall efficiency in converting fission energy to electrical energy of 30%. what mass of 235 U must fission in order for the power plant to operate for (a)one day, (b)one year?(c) if the...

missed a lecture and now have this homework problem and don't even know what the upside down triangle symbol indicates, can someone please give me a hand getting started, thanks consider the vector function q=(1/4X^4 y^2 z, x^3 yz^6 - cosh(xz), 1/7x^3 z^7) calculate f(x,y,z)=upside down...

Trying to make sure my calculations were correct. We were tasked to make 2 grams of NH4Cl. Our proposed method was using HCl and NH4ClOH. This was confirmed as our best way. The way I figured it was that 2 grams of ammonium chloride was 0.037519 moles. We used 6M hydrochloric acid and 6M...

Where can I find worked out quantum field theory calculations? What are the longest calculations in physics? I would like to see them.

Homework Statement prove that if aba-1=b2 then a3ba-3=b8 The Attempt at a Solution Ive tried lots of different things, none of which have worked. i trield left and right multiplying by a^2 and a^-2 but couldn't figure it out. I know there is some magical trick but i cannot for...

Homework Statement This is from Advanced Physics by Adams and Allday, part 8 Modern Physics, Practice Exam Question 15. The spectrum of atomic hydrogen contains a prominent red line having a wavelength of 6.60 x 10-7 m. Calculate the energy of a photon with this wavelength. The...

Homework Statement let a,b\inG Assume that a has order 5 and that a^{3}b=ba^{3} Prove that ab=ba The Attempt at a Solution I know there is some magical thing you can multiply by that will make things nice... i just can't figure this out. if tried left and right multiplying...

Homework Statement assume that the equation xyz=1 holds in a group G. does it follow that yzx=1? yxz=1? The Attempt at a Solution My thoughts are the following: Since in the problem, it does not state that G is an abelian group, we cannot assume the law of composition is...

Appreciate some backup, checking my calculations to see where I messed up - - it's been 30years since college chemistry: Let's say I have a compound X which has a molecular weight of 320, so, 320 grams = 1 mole. Next, I have a 1% stock solution A of that compound X (1 gram...

OK hey guys, I am building an electric go kart for a final project, and I'm just trying to get my initial justifications correct, with respect to the classical physics involved. SPECS: i was the car to be able to reach 60km/h, The total weight of the car will be approx 200kgs. the size...

A child is running at her maximum speed of 4m/s to catch an ice cream truck, which is stopped at the side of the road. When the child is 20m from the truck, the ice cream truck starts to accelerate away at a rate of 1.0m/s^2. Does the child catch the truck? I know to begin, you must create an...

Hello. I just started a first year chemistry course after switching to the sciences from the arts, and wanted to double-check some equations with you because this is a little new to me. I'm good with the qualitative stuff, but the quantitative parts come a little harder. Q1: A sheet of metal...

Homework Statement A ball is dropped from a height of 1.75m. It bounces on the floor and reaches a maximum height of 1.35m above the floor. The ball's weight is 98.5g. a) What is the ball's velocity just before and just after the bounce? b) How large is the impulse that the ball gets in the...

This is less of a strict math problem than me thinking my online teacher is wrong. I will, however, format the question as per PF's requirements, and I think it should be in this forum because it involves my coursework. Homework Statement Essentially, when should I use relativistic...

I had a go at 2 Q's and wanted to make sure I'm doing this right. so here's the first one, and maybe if i went wrong with it I was going to redo the 2nd Q on my own. \lambda = h/p = h/mv (\sqrt{1-((v^2)/(c^2))}) so, an Alpha Particle traveling @ 2x106m/s (mass = 6.645x10-27 kg)...

Hi Guys I hope you can help. I’m currently trying to modify some existing equipment and have a problem that I hope you good people can help me solve. I have a fabricated bracket that currently supports another bracket than runs on linear bearings to position its self. see attached JPG for...

I am designing a sliding vane rotary compressor for a supercharger application on a small horsepower engine, but I am having trouble with the calculations. I have some estimations that I would hope to be correct (or close) but have no way to verify them at this point. One of the toughest parts...

Hi..i was trying out some calculations i found on some site as practice for my exam this Friday and realized that i don't understand at all.. Everytime i tried something..my answers were wrong.. E.i 1. How much heat energy is needed to heat 4 kg of aluminium by 8 (degrees)C? The...

Homework Statement My task was to determine the focal distance and the magnification of a converging lens. I've done everything as stated in the procedure. The problem that i have is that when i am calculating the magnification in two differents ways i.e M1=b/a and M2=h'/h where a=distance...

Some help with calculations please :) So my friend Ryan is building a home made cyclotron particle accelerator. I'm rather interested in building one of my own, but fear I lack the technical know-how and mathematical practice to do so just yet. I asked him how he is building it(on facebook...

Hi, I've been reading these forums for quite a while and now it seems like a good moment for my first post. I'm doing simple coherent transport calculations in tight-binding approximation. The device Hamiltonian matrix H_D is connected to two ideal leads, characterized by the unit cell lead...

I know they must use some sort of wave equation to calculate the exact orbitals of an atom, but I'm interested how they can be so absolutely sure that their calculated configurations are not wrong, what do they use calculus...matrices...etc?

A point charge q_1 = 3.40 {\rm nC} is located on the x-axis at x = 1.80 {\rm m}, and a second point charge q_2 = -5.80 {\rm nC} is on the y-axis at y = 1.10 {\rm m} What is the total electric flux due to these two point charges through a spherical surface centered at the origin and with...

Do you think school should integrate classes that promote mental math and mental arithmetic, for example the ability to multiply two digit numbers in your head (say 15x19 or 14x17, etc). These things are critical and many people can't do them with severe brain gyrations! Do you think enough is...

Hello, I've been trying to learn about electron configuration in atoms, and how it is calculated. I pretty much figured out a lot of it from doing my own research. From what I understand, each group in the periodic table represents a different electron shell, and the blocks S, P, d, and F...

I am new to the forum,so if i posted the question not according to some specific format, i apologize. Power companies typically bill customers based on the number of kilowatt-hours used during a single billing period. A kilowatt is a measure of how much power (energy) a customer is using...

Homework Statement I have 2 problems I'm having trouble with right now.(actually more but I'll ask 2 and try to figure out the others for now. Two blocks are in contact on a frictionless table. A horizontal force F is applied to M2, as shown. If M1 = 1.06 kg, M2 = 3.38 kg, and F = 4.75 N, find...

Hi all! I am a chemist trying to make her way through solid state computational physics problems and I have been stuck with this question for a while and couldn't find a clear answer to it: What is a Zero Point Energy and especially, how can I calculate this for a bcc solid? Anyone can...

I will be do a project soon on a topic that I pick. I am interested in solar energy but one of the requirements for the project is to show calculations related to your topic. Are any calculations that wouldn't be to hard that might be relevant or should I find another topic?

hi, i understand how to use steam tables, but my problem is i cannot tell which phase the water is currently in. i do all the calculations, but how do i choose which phase? i ask because one of my questions asks for phase difference. many thanks jared james

Hello, Can anyone get me Heat exchanger thermal formula and equations Tom

I'm trying to find out how to see if my brakes will lock up or my tires will continue to roll through the following scenario. I have a machine that weighs 42,000 lbs. I'm pulling a 110,00 lbs trailer with load (no brakes on the trailer). This is a rubber tired machine going down a 8 degree...

Hi all, I'm currently learning QFT out of Mandl and Shaw supplemented by Peskin and Schroeder. What are the best books for getting experience with QED calculations? Problems with worked solutions would be ideal.

I'm supposed to calculate the cost of renting a Ford, Cadillac or Toyota, and use conditional statements to calculate the different costs of each vehicle. users are supposed to enter “F” for Ford, “T” for Toyota, or “C” for Cadillac users enter “F” for Ford, “T” for Toyota, or “C” for Cadillac...

Two unlike charges attract each other with a force of 5 x 10^-5 when placed 12 cm apart. 1) What is the force between them when they are 4.0cm apart 2)At what distance apart will the force between them be 2.0 x 10^-4 now i have attempted these questions, but i cannot find a...

Hi, a few months ago, someone pointed me to an excellent primer on lattice calculations, available for free on arXiv. I was browsing and finding many results, so I was wondering if anybody had a good reference, including worked examples so one can readilly do such easy things as calculating...

Hey folks, Sometimes I see the calculation of the vacuum energy written as: \int\frac{d^3k}{(2\pi)^3}(k^2+m^2) and sometimes written: \int\frac{d^4k}{(2\pi)^4}log(k^2+m^2) See for example http://arxiv.org/abs/hep-ph/0105021 equation9. Does anyone know why you can increase the...

i have been set a question to draw the shear force and bending moment diagrams for the loading condition shown on the diagram, and am not quite sure how to do this... do i need to work out other forces along the diagram? and help...much appriciated thanks!

I need to solve this problem: A gas of 5.00 L hydrogen with temperature 300 K and pressure 1.013 x 10^5 Pa. The molar mass of Hydrogen is 2.016 g/mol. a) find the translatinal kinetic Ktr energy of the gass b) if the gass is contained in a container which is moving 300 m/s what is the...

I'm trying to work out the percentage error in working out the value of gravity,g, from a pendulums motion. i know that percentage error is (possible error/value used)*100 however I am using multiple values multiple times and its getting a little confusing. In the investigation g=k(∆T²/∆L), my...

I am having a problem with some thermodynamics calculations. I am not very experienced with them and it certainly shows in my frustration with them! Anyway the check that I am using is incrementally simulated work compared to theoretical energy in. Example 31KJ in 133KJ mechanical work out. I...

[SOLVED] Force Calculations If an object is being pushed horizontally, does Fnormal always equal Fg? And Ffriction only equals Fapplied if it's at a constant velocity? I think that's how it goes, but I'm a little unsure. Thanks!

Help please! Here's the question I'm having problems with: The solubility product of calcium hydroxide, Ca(OH)2, is 7.9 x 10^-6 at 25 degrees celcius. Will a precipitate form when 100mL of 0.10 mol/L of CaCl2 solution and 50.0 mL of 0.070 mol/L of NaOH solution are combined? Do I...

I'm having problem knowing how to work out this question, can anyone point me in the correct direction. Question 14mm diameter steel rod carries a load of 3.08kN in tension. calculate the stress.? I ended up with this: Stress = Force/Area. Stress = 3.08/154 = Answer = 0.02N/mm² if...

any CASTEP users or DFT planewave-pseudopotential method users out there? how do I ensure that the basis set is adequate? I'm performing calculations with a rather large unit cell ( orthorhombic, 8 atoms/cell) of a compound AB. Can I justify my choice of energy-cutoff by testing...

What is the difference between burnup calculations and depletion calculations?

Hi Everyone... I really want to be able to calculate the RA/DEC of a Satellite from TLE data. For example, the International Space Station (ISS) Can anyone help to point me in the direction of where to find the claculations I need to perform this conversion from TLE data to RA/DEC? I...

I am trying to imitate the Airhog zero gravity climber one of these http://www.gmhummer.com/forums/showthread.php?t=111 can someone please help me regarding derieving equations for the suction pressure required and regarding selection of motors for driving suction fans. the toy...

Homework Statement Buffer solution : CH_3COOH (55 mL) + CH_3COONa (45 mL) Ka (CH_3COOH) = 1.76 x 10^-5 Calculate the expected pH of your buffer solution after it has been dilted by making 10 mL of buffer up to 100 mL with deionized water. Homework Equations Ice charts n= c x v c= n/v...

AirFlow Calculations/ Anemometer anyone?? Hello all, I am trying to solve a problem with my anemometer. I am not sure if there is anyone here that has used one but here goes. My purpose is to calculate CFM of a particular AIR INTAKE of my truck. The problems lies in that CFM= Air Velocity...