Homework Help

what is the formula Vf^2 = V0^2 + 2ax used for?

Im working through an assy about electrowinning copper and done some calcs that im not too happy with. Im not too used to working with amps coulombs, KWh, etc so maybe this is the problem. Any comments on my workings would be most useful cos i gotta get it in, along with a load of other stuff! I need to calculate the energy/power required to electrowin 270 tonnes of copper per day from a sulphuric acid solution. Using faraday's laws of electrolysis: 63.54 * I * 24*3600 = 270,000,000 2 * 96,500 => 270,000,000 * 2 * 96500 = I 63.54 * 24*3600 That makes 9.5 million amps per day! The PD between electrodes is 2V so to find power / energy: (95000…

I have this really annoying assignment where I've been told to pick a component from an existing machine and then analyse the likely stresses using traditional pen and paper methods, then using a finite element approach to compare the results. I need help thinking of a component complicated enough to turn my lecturer on. Any ideas?

I have a homework question which I am stuck on part of it... A particular car radiator works by the hot air from the car conducting heat on to medal fins in the pipes. What does the color of the tubes have to do with the radiator? I was completly stuck on this... any help appreciated...

I'm looking for a professional in the field of Cardiology or Neurology. For a school project, I'm required to interview them asking questions regarding their profession and field of work. Although this forum isn't exactly meant for that... I couldn't think of a better place to look for such professionals. Help is appreciated, please post in reply and I shall pm you the interview questions.

M = -M^t where M is 3*3 prove that det(M - kI) = -det(M+kI) Ok for starters its a square matrix => M^t = M => M = -M for our matrix So to get to our proof my solution would be; det(M) = det(-M) det(M)(I-kM^-1) = det(M)(I-kM^-1) det(M - k I) = det(-M + k I) Unfortunately as you can see this doesn't give the answer... any ideas?

Hi, I have a practical to write up, have managed to plot a graph with lines to show Vmax plus 1/2 Vmax...the problem I have is the maths bit, I simply canot remember what I need to do. So far I have worked out Km.....say is 0.75mM on my graph.....substrate concentration e.g is 2.4mM what calculations do I need to do so I can proceed to the next stage....as I will have to do a Linewaver Burk plot afterwards. Any help gratefully received. Mel

I have done a few Spectroscopy questions already, However I am having troble with these last three problems. Any help would be GREAT! Here is the link tothe spectroscopy questions. On worksheet 6b, I need help on #1 and #2. On worksheet 6a I need help on #4. http://chemistry.usf.edu/faculty/data/weldegirma/files/worksheet6-2210L.pdf

Okay I'm CERTAIN this is an idiotic question, but I'm stuck, so.. help. The question is as follows: This isn't a hard question for part A.. this is what I did: disp('--(a)-- With For Loop:'); %calculate max value (to compare to): t=4; x=5*t-10; y=25*t^2-120*t+144; minDist=sqrt(x^2+y^2); for t=0:0.1:4 x=5*t-10; y=25*t^2-120*t+144; %calculate distance: Dist = sqrt(y^2 + x^2); if Dist<minDist minDist=Dist; minT=t; minX=x; minY=y; end end Xminimum=5*minT-10; Yminimum=25*minT^2-120*minT+144; TimeForMinimum=minT MinimumDistance=minDist But I'm getting stuck at part b, where I'm nto supposed to use "for…

I Have a question about the following reaction: H2 + CuSO4 ----> Cu + H2SO4 I have to find the heat of reaction for the equation in lab, i'm using Hess' law and i have the theoretical heat of formation for both copper sulfate and the sulphuric acid, but i'm not 100% sure of how to find them in the lab. I'm using a temp. probe with a home made calorimitor (hope thats how you spell it). will i be able to react straight copper with the sulphiric acid? and does anyone have any ideas? any help would be greatly appreciated.

I need to work out the equation for the reaction between potassium dichromate(VI) and ammonium iron(II) sulphate, but I just don't know where to start...any pointers?

Ok so I have 2 points A = 2 + 3j C = 4 + 7j on our argand diagram they make an equailateral triangle with a point (or more precisely either of 2 points) which I'll call z Now I know; [math] ABC = arg ( \lambda ) = arg (\frac{a - b}{c-b}) [/math] so [math] arg(\lambda) = \frac{\pi}{3} [/math] and [math] \lambda = \frac{a-b}{c-b} [/math] [math] \lambda = \frac{(z-(4+7j))-((4+7j)-(2+3j))}{(z-(2+3j))-((4+7j)-(2+3j))} [/math] [math] \lambda = \frac{z-6-11j}{z-4-j} [/math] No where do I go from here; solve simultaneously, or am I using the completely wrong method? I've attatched a sketch of the argand diagram.

This shouldn't be too dfficult I need to prove (e.g.) ; [math] b_1A_1 + b_2A_2 + b_3A_3 = 0 [/math] Ive managed to get; [math] a_1a_3b_2 + a_1a_2b_3 - a_2a_3b_1 + a_2b_3a_1 - a_3a_1b_2 +a_3a_2b_1 [/math] which nicely cancels out with the exception of 2 terms; giving; [math] 2a_1a_2b_3 [/math] Can anybody see where I've gone wrong?

What is understood by the term 'atmospheric nitrogen'? Does it refer to nitrogen as N2, or to nitrogen oxides? And through what type of mechanism would acid rain be formed from this atmospheric nitrogen? I've been trailing through textbooks and internet sites all afternoon with niot much avail! So any help at all would be appreciated =)

hey everyone im doing this thing on nuclear fission and the more i read the more confused im getting lol, some questions: Are there any other decay reactions insides a nuclear core besides ‘236U – Ba + Kr + 3n’ How are slow moving neutrons injected into the reactor core of a nuclear power plant If fast moving neutrons from a fission reaction cannot effectively enter a nucleus and initiate fission more fission (too fast), how does it work in a fission bomb? Is there a moderator present? ty

My 1st physics test in coming up, so I'll probably have a few questions... so might as well make one thread for it... OK, first problem should be relatively simply, but I keep hitting dead ends. A race car constantly accelerating travels a 140 m distance in 3.6 seconds. If the final velocity is 53 m/s, a) what was the initial velocity of the interval. b) how far has the car traveled from rest. Now, it looks simple enough, but without a given value of acceleration I seem to be stuck. I try to solve for velocity in terms of a, and plug it in to a different equation to solve for a. But, it's not going in nicely, and I'm not getting an answer. I…

Question: Find a Maclaurin approximation to calculate [math] \frac{1}{\sqrt{e}} [/math] so I go for the M.A of [math] {e}^{-0.5x} [/math] which I have worked out to be [math] 1-0.5x+\frac{x^2}{2!}-\frac{0.5x^3}{3!}+\frac{x^4}{4!}-\frac{0.5x^5}{5!} [/math] But If I now dow f(1) it does not approximate [math] {e}^{-0.5x} [/math] (although it does around f(0)) Any help?

I am doing a physics assignment on basic mechanics of a rollercoaster i have written it all up apart from the section on future developments in this area of physics. I was tinking about doing it on space advance since there is alot of mechanics, does anoyone have any other suggestions or knows of somthing quite unique to do with mechanics of free fall that you can refer me too to create a more interesting project?

hey i have an assignment on astatine and i need help i need to know where it is found what ore it is found in how it is obtained what it is used for compounds its found in who discovered it what year it was discovered in how it got its name and anything else useful. please help me with this. its due on wednesday!!

Hi everybody. I have to write a 5-7 research/cause and effect paper on any topic, and I would like to pick something related to Biotechnology, Chemical Engineering, Bioethics, etc that is not about abortion, stem cell research, or any of the widespread current debates that never seem to end. Anybody have any good ideas?

I have this question to do.. and I've been stuck on it for AGES! Please help! Calcium in a sample solution was determined by atomic absorption spectrophotometry. A stock solution of calcium was prepared by dissolving 3.668 g CaCl2.2H2O in water and diluting to 1000 cm3. This was diluted 1:10. Standards were prepared by diluting the second solution, respectively, 1:20, 1:10 and 1:5. The sample solution was diluted 1:25. Strontium chloride was added to all solutions before dilution. Absorbance signals, when the solutions were aspirated into an air-acetylene flame, were as follows: standards, 9.1, 18.6, 37.0; sample 20.9. What was the concentration of calcium in the samp…

Ok so I need to solve; [math] z^{5} + x^{4} + z^{3}+z^{2}+z + 1 = 0 [/math] My first thought is to use the summation equation where a = 1, i.e.; [math] \frac {1-z^5}{1-z} = 0 [/math] but then I'm not sure where to go from there; in the past I have had something^something else = 1 then something = alpha and then made z = f(alpha) however here there isnt a whole term to the same index. Any ideas?

I have to do a presentation on motion for the 2nd... powerpoint. I need to find a news article from a valid source on motion(issues in the news) and a supporting article that doesnt have to be valid. I was thinking about speed of light but that is really hard for me... Can anybody help... give me any ideas what i should do it on :\ and maybe a news site that may have it? Thanks everyone

I was just wondering if anyone could confirm my anwsers for 2 questions. 1)Explain the fluorescence of the chlorophyll bands. Did the spinach leaf fluoresce? If not, why not? The spinach leaf fluoresced because a molecule’s electron reached an excited state, resulting from the absorption of a photon by a pigment, and when this electron returned to its ground state, the resultant accompanying loss of energy is given off as another photon, fluorescence. The graph of the relationship between absorbance and wavelength illustrate this in the drastic drop in absorbance. As the graph suggests, this only occurs once which is why we only saw the fluorescence appear once o…

We are required to find a product that can be produced using "C a r o b". Any idea for what I can produce? I also need the procedure for it. Please don't write the word "C a r o b" as one word because my classmates are on the run to find one too! Thanks !