Homework Help

Hello everyone. I attend a course of seminars called "English for scientists" and I have a homework to ask some question on your nice forum. So I hope you'll help me to kill two bunnies with one shot by solving a problem and executing a task. Now, to the question. I supervise scientific work of a couple of 4th year students and they are not very willing to spend their whole days in laboratory like me and my collegues. They sure are able to handle with great amounts of work when they feel it is necessary, but mostly they manage to find good excuses to not attend laboratory, which results into reducing quality of their researches. What can I do to make my students work…

When it comes to formal proofs I have no idea how to even start it. When do I use a subproof and how to use it? Can someone please explain to me when to use a subproof and how to start a formal proof? Please and thank you. This is what I have so far...and I have no idea what to do next...

Hi everyone, how would you expect hepatocytes to take up sodium acetate from the culture medium? Cheers

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Hello, I need Help solving the diffusion PDE using Green function. I attached the file with the question. Any help would be greatly appreciated. Thank you!

Im stuck on this practical question below because i believe i don't have enough information to answer it. If anyone could point me in the right direction it would really help: -Calculate the mass of a compound with a molar mass 392 in 100cm3 of solution All i know was to: accurately weigh 0.7g of this compound and transfer it into 100cm3 graduated flask containing 80cm3 distilled water. shake to dissolve and then make the solution up to 100cm3 with distilled water. As im being asked to calculate the mass of the compound i cant use the 0.7g (as i'm supposed to be calculating this), i cant use mass=conc X volume as i don't know the concentration. so i can only think …

Hi, I am working on marine turtle ecology and I have ended up taking a project where I am looking at Sea Surface Temperature in relation to their behavior. However, I am having difficulty in getting the SST data in a simplified form. The SST data that I got from the met department of my country was horribly inconsitent. So basically I am looking for a simple data set giving the SST on a daily/monthly basis for a given area. Can anyone help me get this? I need numerical values and not maps. The ones i have come across...either I don't know how to access the data or it is to intimidating for me to understand. So much technical lingo! Thanks in advance!!

Given |a|=3, |b|=5, and |a+b|=7, determine |a-b|. (a and b are vectors) how to start this?

Can you please help me in this question Nitrogen (molar mass 28kg/kmol) expands reversibly in a perfectly thermally insulated cylinder form 3.5 bar, 200 oC to a volume of 0.09m3. If the initial volume occupied was 0.03m3. Calculate the work done during the expansion. Assume Nitrogen to be a perfect gas and take CV=0.741KJ/KgK Thank you

What pH will the solution produced by reacting sodium in water have? Thanks!

Hello all, i am new to this forum and this is my first time posting, I have been assigned some coursework in chemistry that requires me to look into rates of reaction and what effects the reaction. This is the study brief: One chemical that is made industrially is sodium thiosulfate. Sodium thiosulfate solution is sold in a range of concentrations. Dilute solutions of sodium thiosulfate can be used for cleaning contact lenses and used as a medicine for some cancer patients. Concentrated solutions are used to treat spillages of some chemicals. Sodium thiosulfate is safe to handle and store, but if it is mixed with an acid, a reaction happens. When dilute sodium…

Hi guys, I was hoping you could give me some tips on how to answer a question on gel electrophoresis. I am examining how 2 lactate dehydrogenase components (muscle & heart component) are travelling through a gel. The question asks how LDH travelling through the gel would be affected by a decrease in the pH. Thanks!

I'm introducing my daughter to math and I can't remember if there's a quick rule to check if a large number is divisable by 7 and 8 at a glance. 1: if it's whole 2: if it's even. 3: if the digits add up to 3,6 or 9 4: if the 10s digit is even and the 1s digit is 0,4,8 or the 10s digit is odd and 1s digit is2,6 5: if it ends in 0,5. 6: if 2 and 3 both work. 7: ? 8: ? Can't think of a simple rule 9: digits add to 9 10: ends in 0 0: everything is divisable by 0. Haters gonna hate. ... I think when I was in school they said there wasn't one for those... But they said the same thing about 4.

Hi there everyone, I'm conducting research into human perception of audio quality within recorded music (playback formats) as part of my Masters degree. I'm looking to gain some insight into listening habits as part of this research and would really appreciate your help in filling out this short survey (link below) which should take no more than a few minutes https://docs.google.com/spreadsheet/viewform?usp=drive_web&formkey=dHkyQ0FfcEFNRlpoQzNZejkzNlZpTGc6MA#gid=0 thanks in advance Dave https://docs.google.com/spreadsheet/viewform?usp=drive_web&formkey=dHkyQ0FfcEFNRlpoQzNZejkzNlZpTGc6MA#gid=0

For chemestry we have to do an experiment with beer. We have to brew beer and add something to change the beer. The brewing process is not a problem for us, but we were thinking of the idea to add gelatin to the beer. A part of the experiment is to analyse the change of the beer with a chemical method. The more "exotic" the method or analysis is, the higher we will be marked. So we are asking for any help for finding a good analysis and in what way we should use this method. We would really appreciate if someone could help us with this problem.

Hi there, im doing an doing a question from a tutorial sheet in power engineering, here is the question: (im not looking the answer to the question) A ferromagnetic core has mean path length l1 of 50 cm. There is a small gap of 0.1cm in the structure of the otherwise whole core. The cross-sectional area of the core is 15 cm 2, the relative permeability of the core is 4000 and the coil of wire on the core has 500 turns. Find: (1) the total reluctance of the flux path (iron plus air gap), and (2) the current required to produce a flux density of 0.6 T in the air gap. What I am unsure about is the when i look at the solution to the question I understand …

The questions is: A 400-turn circular coil (radius = 1.0 cm) is oriented with its plane perpendicular to a uniform magnetic field which has a magnitude that varies sinusoidally with a frequency of 90 Hz. If the maximum value of the induced emf in the coil is observed to be 4.2 V, what is the maximum value of the magnitude of the varying magnetic field? First: I applied the the equation emf=-d(phi)/dt Second: Since we know that Phi(magnetic flux)=BA, we can say that emf=-(N)(d/dt)(BAcos(theta)). Where "theta" is equal to zero because the field is perpendicular to the normal of the area of the coil. The problem that I encountered was that when you take the deriv…

Hello everyone I made myself a question about a car flying of a cliff.. The problem is: the answer seems pretty unrealistic to me: A car drives, when he's at 20 m of the edge of a cliff with a height of 147.63 m, at a velocity of 65 km/h and at a constant acceleration of 10 ms-2. Determine how far the car will land of the edge of the cliff. To do this, I'll use the formula [math]y=y_0+x\cdot\tan{\theta}-\frac{g\cdot x^2}{2v^2\cos^2{\theta}}[/math]. I will thus need the car's velocity when its on the edge of the cliff: [math]v = v_0 + a\cdot t[/math] [math] x = \frac{at^2}{2}[/math] [math]t^2 = \frac{20\cdot 2}{10}[/math] [math]t = 4s[/math…

Prove, that a set Af of points, where exists limt→x+ f(t), but f is not continuous function in x, is a countable set. Thank you, I dont know, how to prove it.

Hello, I need to make a presentation about an article about computer science for a class in college. I was wondering if someone knows an interesting, scientific article about computer science in English (or Dutch). Thanks in advance.

Hey guys, Please help me and solve the question below. (Link to images) Please post your solutions with steps. Thanks in advance. http://i.imgur.com/2MuyoGA.png http://i.imgur.com/Ia2mj0t.png

Hi guys, The question is: Initially a piston cylinder contains air at p1=3.2bar (absolute) and the contained volume is v1=158m3 at temperatuer t1=303k. The air is then compressed, with compression ratio r=v1/v2=5.3. the polytropic index of compression is n=1.3 estimate the net heat addition in KJ. With p2 found in my working, do i need to add my p2+p1 ? Thanks

1. The reaction catalysed by an endonuclease. Which bond is hydrolysed? What are the products? 2. The reaction catalysed by a 5’to 3’ exonuclease and 3’to 5’ exonuclease. ?? 3. Denaturation of DNA. Denaturing agents. Which interactions are broken? Is the process reversible?

we have had civilization on Earth for perhaps only a few thousand years. Could you as a native speaker tell me what you understand from this sentence? Could you please tell me the reason why "likely to be far older on average than ourselves."? Source:http://www.ieltsg.com/search/label/reading%20practice%20test

Hello, I was wondering how signs are assigned to gravitational potential energy. Ug is positive when an object starts at rest and falls straight down. This makes sense to me because the gravitational pull of the earth (Fg = mg) pulls the object a distance of h (thus = mgh). This fits the work equation = Fdcos(theta). But if this is case, shouldn't Ug be negative, because Fdcos(theta) = mg*(-h)cos(theta), where -h is from the object moving along an arbitrary negative axis, and cos(theta) is 1 because the force and displacement vectors are parallel. Any enlightenment is appreciated.