Cell Definition and 899 Threads

Is there a difference between the mass of a battery cell which is charged and the one which is drained? If yes, is difference of the two values proportional to the total work done by the cell (including loss due to resistance), with c^2 as the proportionality constant?

Hello I am trying to store function handles in an array. First attempt was to do something like the following: for i = 1:5 r(i) = @(x) [grid(i) - x(1)*(x(2) + value(i))]; end So I would store 5 function handles, each one using the <5x1> vectors "grid" and "value". Result: Nonscalar...

How to calculate the voltage produre by solar cell ? Need temperature reading or other apparatus ?

Homework Statement A 75.0-W light bulb is powered by connecting it to a standard 12.0 V auto lead-storage battery. How much energy (J) is required to keep the bulb burning for 50.0 continuous minutes ? Assume 100 percent efficency.Homework Equations 1 watt = 1 J/s 1 J = 1 C x 1 V The Attempt...

Hey folks, I am currently doing some research on hydrogen fuel cells as part of a project. I just wanted to clear up some confusion I am having with the whole *platinum issue.* Very generally speaking, this is what I have gathered on H2 Fuel cell vehicles: 1) Electrolysis is needed to...

What is the potential of this cell ( in V) at 25 oC if the copper electrode is placed in a solution in which [Cu2+] = 5.1×10-10 M? I found this answer to be 0.065 which is correct. The second part: If the copper electrode of the above cell is placed in a solution of 0.270 M NaOH that is...

Is Fe2+(aq) capable of reducing Sn2+(aq) to Sn metal? The standard reduction potentials from my book are -0.14 for Sn2+ and -0.44 for Fe2+ Because Sn has a more positive Epot it has a greater tendency to be reduced. So add the Epot up: -0.14 + 0.44 (oxidation)= 0.3. It's positive...

Hello! Right now I am trying to figure out how much of an affect dust has on the power production of some solar cells that I have. I was just searching for a possible material to use for dust testing. Anyone have any bright ideas?

I was playing with Wolfram|Alpha, and I typed in my ten-digit phone number. And it was prime! I have a prime cell phone number! Of course, I tried this with other numbers... my SSN isn't prime, and neither is my dad's phone number. My seven-digit phone number can be divided by two square...

Hello guys, So there are hydrogen ions inside the cell which is pumped out in cellular respiration. Now my question is when they say hydrogen ions are inside the cell are these actually dissolved in water, ions can not exist without being dissolved right, why is that they are so reactive...

I think I got a and b, the rest I did my best on, and I could use some guidance! Thanks!Homework Statement 1. [6] Methane (Natural Gas) Fuel Cell. Consider a fuel cell that uses methane as fuel. The chemical reaction is CH4 + 2O2 = 2H2O + CO2 + energy (a) [0.5] Measurements reveal that...

Homework Statement In a galvanic cell, the electrode that builds up a precipitate of metal (known as plating out) is: A. the cathode, and its surface is rich in positive charge. B. the anode, and its surface is rich in positive charge. C. the cathode, and its surface is rich in electrons. D...

Hello all, I am an AP Chemistry student currently studying electrochemistry. The other day, some friends of mine and I discovered some waste copper oxide laying around the lab. We thought, "Why not reduce all the copper out of this?", and so we set to work. We got our experiment...

Hi, I'm working on a commercially available PEM fuel cell and I'm trying to calculate the theoretical voltage of the cell: The only electrochemical reaction considered is H2 + 0.5O2 --> H2O And I understand that I need to use the Nernst equation: E = EO - (RT / 2F) ln (PH2O / (PH2 *...

http://www.wrcbtv.com/Global/story.asp?S=12166928 http://www.businessweek.com/ap/financialnews/D9ED5BI00.htm http://www.heraldnet.com/article/20100313/NEWS01/703139877&news01ad=1 http://www.kimatv.com/news/local/87601672.html http://blogs.zdnet.com/cell-phones/?p=3263 I think the...

I tried connecting my solar cell, 7V/100mA to the ammeter. What I got is 1mA. Why? The voltage part is 6V, so I assume the efficiency should be at least around 6/7*100 %. But why is it only 1mA? I connected the solar cell straight to the ammeter. I need help fast. Thank you.

Hello. As a memorial I am trying to build a light-sensitive unit that will make an LED continuously glow at night. I want to put this in an extremely remote place and be reasonable confident that it will continue to operate indefinitely. The idea is that once it becomes dark, a photodiode will...

If a person loses enough blood to become moderately anemic, how long does it take for the red blood cell count to return to normal? I mean roughly...would it be on the order of days, weeks, or...? Is daily iron intake a typical limiting factor in this process?

im asking this because chemically they are very similar, and the only big difference i see is that potassium is much larger. i got the details for mammalian cell typical ion concentrations and it is such: inside outside (mM) K+ 5-15 145...

I have a few questions, first of all I'm trying to figure out how to find the volume of a 3 dimmensional wigner sietz cell. I have the 8th edition intro to solid state physics book by charles kitle and there is no where in the book that shows me how to find the volume of wigner seitz cell...

Go to: http://www.txt2day.com/" Enter the 10 digit phone number, no dashes Return e-mail (optional) You select the destination cell phone's provider Normal tweet text message Answer the anti-spam question (don't forget or the message won't be sent) Press send... That's it... Rhody...

How do I type in an e-mail address on a cell phone (are the letters just the numbers just as when dialing)?

Hello, I have a Nokia 6300i cell phone with double flash camera. The camera's flash was just working fine in the begining, then in one day I tried to capture a photo in the night with flash turned to automatic and it did not work. Then, I turned the flash to be on all the time, but useless...

What are the cell potentials of the following? 1) ZnSO4 (1M) & CuSO4 (1M) 2) ZnSO4 (1mM) & CuSO4 (1mM) 3) ZnSO4 (0.1M) & CuSO4 (1M) I tried using the nearst equation and I keep getting that they are all the same value of +1.10V

Hi, I'm looking for information on blood and neuron cells. Specifically I need to know how the membrane transport mechanism in blood and neuron cells work? I am aware of concepts such as active diffusion, facilitated diffusion, and simple diffusion. The task is to look at the membrane...

i was wondering what are the chemical reactions involved in producing the electricity, that the batteries provide i.e. the reductant and the oxidant

To send a signal, how much power does the microwave transmitter use?

A diagram shows a flexible copper wire attached to the terminals of a dry cell. A strong circular magnet, 12 mm in diameter, is attached to the side of the cell. The interaction between the current in the wire and the magnetic field of the magnet causes the wire to levitate i.e. _____+ l...

i am learning femlab 3.1...so following the model library given with the set of books.. but i am facing problems with the 3 d modelling.. as in case of fuel cell stack model..the solver is unable to solve even if all the steps are followed according to given instructions.. i have double...

1. Karen and Steve each have a sibling w/ sickle-cell disease. Neither Karen nor Steve nor any of their parents have the disease, and none of them have been tested to reveal sickle-cell trait. Based on this incomplete information, calculate the probability that if this couple has a child, the...

Trying to teach myself electrochemistry out of a textbook and it's kind of confusing at some parts without any teacher to ask questions, but I think I'm doing a pretty good job. I've got a test tomorrow on this stuff and I'm kind of burned out from studying (about 20 hours in the past 4 days) so...

The question is related to impedance cell counting, determining cell`s size etc. This method is working like this: "A small portion of the diluted fluid in each bath is allowed to flow past a small aperture. An electrical current is produced in each aperture by two electrodes, one on the...

I’m from a group that is current working on the theory of a Hydrogen Economy. Our first area of development is the Hydrogen Highway. We are currently seeking help in the form of freelance / work for hire basically engineer(s) that could aid in design and calculations of internal combustion...

I've heard that the human body completely renews all of its cells in seven years; the pancreas in 24 hours. I've been trying to find a website that lists the turnover rates for each organ, tissue or type of cell. If anyone has a link or a book with that kind of information, let me know...

My mother has always insisted that I have a cell phone with text capability. She says that she's heard that sometimes when cell phone service is not available, people will still be able to send text messages. I believe she's thinking that after a natural disaster, like an earthquake, all the...

As the solar cell gets further away from the light source, does it get more efficient or less efficient? At the moment I am able to work out how much power enters the solar cell. However, it is pretty weird because as I found out from my experiment, the efficiency of the solar cell gets better...

http://www.msnbc.msn.com/id/34502456/ns/health-cancer/ Maybe this is the excuse I need to tell people to stop calling me with meaningless dribble.

Is there are way to find out power from lux entering a solar cell? I currently have the area of a solar cell 127.2 cm square, and the lux reading 8434 lux I have heard of the equation watts per metre square. However that's not the equation for lux right?

You are given the following materials:  Silver wire  A 0.10 mol L-1 solution of cadmium nitrate  Cadmium wire  A 0.10 mol L-1 solution of silver nitrate  A salt bridge  Copper wire  Beakers and other glassware as required Draw a labelled sketch of your cell. Describe...

I want to charge a single lithium-ion cell from a current-limited voltage source. My "black box" (or rather, it's white -- with a question mark inside) has inputs of ~250mA @ [3.7V to 5.4V], and target output (i.e., the lithium-ion cell) of 3.2V to Vch = 4.2V. Which means: I can't charge the...

Hi, I've been reading up on multijunction solar cells and found out that since the different layers are connected in series the photo generated current through them must be adjusted so it is the same for each layer to conserve efficiency. Why is that? thanks.

Hey Guys, I'm a mechanical engineer (please forgive my ignorance) with an electrical engineering problem. I'm trying to control a small DC motor with speed and duration controls using a remote cell phone. I might also like the ability to receive temperature data from the motor back at the...

Basically I want to Calculate the internal resistance of a solar cell. I set up a circuit with a voltmeter across the solar cell and an ammeter and variable resistor in series with the solar cell. The variable resistor is the load. Image at...

Pacing in my office this afternoon, talking with my dear old mother on my cell phone; I happened to observe a brief power outage. A bump, or surge, if you will. It was a loud buzz (no transformer around me that I know of), lights went out, and strangely enough it knocked out my cell phone. I...

I was using my iPhone when I got to thinking about how amazing it is that so much information can be transferred all with electromagnetism. I was in a room with 500 other iphones and I could not connect at all. is this because AT&T could not support 500 people on the same tower? if someone...

Homework Statement Determine the mass of sodium deposited at the cathode of a molten NaCl(l) electrolytic cell if 10.0 A flow through the cell for 2.00h. Homework Equations The Attempt at a Solution For the mole ratio, Na+ +e --> Na 2Cl- --> Cl2 + 2e Should I balance the...

Homework Statement The average cost per item, C, in dollars, of manufacturing a quantity q of cell phones is given by the following equation, where a and b are positive constants. C = a/q + b (a) Find the rate of change of C as q increases. Include units. I already found this, it's: -a/q^2...

Have totally confused myself looking on line for a good phone. I was excited about jitterbug because it was simple and seemingly made for exactly our family needs. However the reviews leave me thinking I should ask advice. We need two Very Simple phones with a simple service. In the NY area...

I'm looking for a cheap solar cell for an experiment that we're doing on different sunblock lotions. Will a clear sunblock lotion (say spf 50) affect the ability for a common solar cell to produce electricity? If the answer to the first question is no, is there a solar cell that does use...

Homework Statement Calculate the potential of a Zn^2+/Zn and Ag^1+/Ag couple. Homework Equations Zn^2+ + 2e^1– ⇌ Zn E= –0.76 V Ag^1+ + e^1– ⇌ Ag E= +0.80 V The Attempt at a Solution First I know to multiply the silver half reaction by...