Homework Help

Help with Torricelli - viscous -------------------------------------------------------------------------------- Hey everybody. I'm an undergrad in mechanical engineering and I'm having some trouble with a fluid mechanics problem. It's an extra credit problem so it's a little over my head. Anyway, we have a tank with water at height H and a stopped pipe at the bottom of length L (horizontal - think of a Torricelli problem). At time t the spout is removed yet the height H remains constant (somehow). I need to derive the following equation for the velocity coming out of the pipe and I'm not sure how to start. V = sqrt(2gh)*tanh(sqrt(2gh)t/2L) I realize that …

Hello everyone. My name is Dan A group of colleagues and I are writing a Research Funding Proposal (RFP) here at NC state university. While we are not actually turning this in to get funding from an agency, we are, however, doing it for a grade in the class. This is to ensure that we, as rising scientists in our own particular fields, have the necessary and fundamental knowledge of how to go about doing funded research. My question is: Could someone please give links to online PDF's and Full-texts concerning Oxytocin, Cortisol, Dopamine, Serotonin, Vasopressin, and Phenylethylamine (PEA), so that my colleagues and i could review them, and make decisions on t…

The problem: A concrete highway curve of 80 meters is banked at a 19 degree angle. What is the maximum speed with which a 1800kg rubber-tired car take this curve without sliding? (static coefficient of friction of rubber on concrete = 1) So would I set up something like this? The answer is 40.1m/s, but I get 31.6m/s. So I need help to figure out what I'm not getting. I have the force of gravity in the y direction equal to 16,679.0N and in the x direction it is equal to 5,743.0N. The max friction would equal the normal force since the coefficient is 1, so the max friction would equal the force of gravity in the y direction. Add the max friction and Fgx and I have…

There are 2 blanks that I could not remember could someone help plz

The question is: Oxalic acid, H2C2O4•2H2O (molar mass = 126.07 g/mol) is often used as a primary standard for the standardization of a NaOH solution. If 0.147 g of oxalic acid dihydrate is neutralized by 23.64 mL of a NaOH solution, what is the molar concentration of the NaOH solution? Oxalic acid is a diprotic acid. (Hint: what is the balanced equation?) My calculations (which the lab site said were wrong) are as follows: 0.147g/126.07g/mole - 0.001 mole (oxalic acid) M (moles/Liter) = (0.001 mole / 0.02364 L) X (2 mole NaOH / 1 mole acid) = 0.085 mole/Liter NaOH. is this right and I should disregard the site, or where did I mistake?

Hi! I have 2 independent groups that I already know the means for, and I know the sample variances are equal. Both means and the sample standard deviation are given in the problem. Group 1: Mean=1000, based on average last year Group 2: Mean=976.3, based on a random sample of 36 this year. s=47.8 Question: Is this year's mean less than last year's? I know how to do an independent samples t-test by hand, and interpret results. However, my instructor said to use SPSS whenever possible. Therefore, if the raw data isn't given, is it possible to use SPSS? Thank you!!!!

Today I was given a sheet by the science teacher, we are to read a few pages out of a text book and fill in these blanks. I filled in most of these but I can't find the following 2 . Could someone please help me? The genetic chemical which makes up your chromosomes and those of all ____________ things is called deotriboncleic acid or dna for short. The genertic code is stored in the 3 billion nitrogen bases of dna, arranged in about ________________ genes on the 46 human chromosomes Here below is prove that I did everything else, this is not helping me cheat. This is not a test only a worksheet and I wanted the answer before tomorrow

Yup, yup. We know that Hydrochloric Acid + Zinc makes Hydrogen gas. But, I don't know. What concentration of acid should I use? High school lab project. I need to produce a fair amount of hydrogen...not too much. Enough to fill an emu egg. I have 12M HCl at my disposal..but I don't want to use something so concentrated. I'm just trying to think what a good, safe concentration would be. I can easily dilute it down to whatever I need...but... I am not worried about the method, steps or equations of arriving at this conclusion, but a general understanding of what you are thinking is great I obviously would like to learn about your conclusions...but pushing m…

I have a test tomorrow and I didn't have enough time to ask my tutor all of the questions for the test. Please tell me how to answer some or all of these question. 1) What forces will be overcome to melt 5 grams of solid C2H6? Explain? 2) A stream of methanol (CH2O) flows past a positively charged object. a) Will the stream attract to the object or will it flow past the object without visible effect? b) Explain your response in a) (Hint - include molecular structure to support explanation) PLEASE explain and answer some or all of these questions as soon as possible!!!!!

Hi Everyone I am new to this forum. So Hello all. Also believe it or not it was only a coincidence I found this site (Its lame so forget it) I can not find any info as to what these interesting structures are. Can someone help me out? I am just going to scan the structures to my printer. Oh yeah. I forgot, I dont want the answer, I actually want to be able to know this because I have a test on this soon... so.. any help would be appreciated... Thanks!

A world-class sprinter accelerates to his maximum speed in 4.2s . He then maintains this speed for the remainder of a 100-m race, finishing with a total time of 9.3s . What is the runner's average acceleration during the first 4.2 ? What is his average acceleration during the last 5.1 ? What is his average acceleration for the entire race? ============================== An alert hiker sees a boulder fall from the top of a distant cliff and notes that it takes 1.30s for the boulder to fall the last third of the way to the ground. You may ignore air resistance. What is the height of the cliff in meters? ====== A marble is released fr…

My thermodynamics professor gives us the theory during lectures, and then we are given problems to try to solve for homework. I always have trouble applying the theory for the first couple problems. I have a few problems of this type, and once I get through one of them, I should be able to do the other ones. It's just a matter of trying to figure out how to bring the theory into application. Anyway, here's the question and my thoughts (I haven't worked anything out like this before, so my thoughts may sound ridiculous, just let me know): Two forms of solid phosphorus are white (a cubic crystal) and red (a triclinic crystal). The [math] \Delta H^{\circ} [/math]…

I have a mixture of: --benzoic acid [C6H5COOH] --phenol [C6H5OH] --hydroquinone [C6H4(OH)2] --dimethylether [H3COCH3] I understand that I can add sodium bicarbonate to get two layers, the aqueous layer containing C6H5COONa. To the remaining ether layer, I can add NaOH to get C6H5ONa and water in the aqueous layer. The question I'm working on now asks what would happen if I added the NaOH before I added the NaHCO3. I understand that if I added the NaOH first, it would react with both the phenol and the benzoic acid (right?). However, would the sodium bicarbonate react with the hydroquinone? I don't think it will because hydroquinone is too weak of an acid. …

I am so confused, specially (AGAIN!!) about my vectors in this equations.. The question: (V is potential). The way I understood it, the energy stored in this configuration is the one involving the potential inside + the one involving potential outside of this sphere. They're both, obviously, different. So, I tried to see if I can first define the two Vs (in and out) and then integrate the W equation. For the potential inside the sphere, I created a "gaussian surface" with r smaller than R, here's what I did: [math] V® = \int_{0}^{r} 4\pi \left( \frac{1}{3\pi \epsilon} \right) \frac{kr'}{r'} r'^2 dr' = \frac{1}{\epsilon} \int_{0}^{r} kr'^2 dr = \frac{k…

http://cemc.uwaterloo.ca/Contests/past_contests/2001/2001FermatContest.pdf Number 16. I honestly have no clue

I have a really bad stats teacher and I'm really struggling to understand the work in his class. Can anyone help with this question? 20,000 men attend NDU, a university whose athletic mascot is the leprechaun. The mascot requirements demand a person no taller than five feet. If the mean height of men is 5'8" with a standard deviation of 2.5", and the student body forms a normal distribution for height, a) how many potential leprechauns are there in the student body? b) how many men are as tall or taller than 6'5"? I don't just want an answer. I want to know how to get to the answer. If anyone can help that would be great.

Hey guys, I have a hw question I'm completely stuck with.. I know which formula I am supposed to use, and I know how, in theory, this should be solved, but I'm having trouble seeting up my vectors. This is a problem I'm constantly having.. I know how to generally solve questions like these, as long as the vectors are 'easy' (on the origin, or stuff like that). The moment the vectors are a bit more complicated, I confuse myself to oblivion. So.. help me out, please, and if you can, explain *how* you do this, so I can finally get rid of my uberconfusion over these type of questions... So, I know that the electrostatic potential can be found by: …

hey guys, would just like to say hi. Im new here so please bear with me.The only way to start my thread is to be honest, so here goes. I have recently started a couse in biology. I now know that i jumped in the deep end and im drowning slowly. The frst course is science (book 1 global warming). And i have'nt got clue, having NO scientific knowledge whatsoever. Yes, i would be lying if i said i did'nt want answers, so i need serious help with understanding with the veiw to finding the answers, does that make sense? many thanx carl.

A negatively charged, graphite coated sphere is suspended from the ceiling on an insulating string in the region between opositely charged parallel plates. The plates are 20cm apart, and are maintained at an electrical potential difference of 3.1*10^2. The charged sphere experiences an electric force of 8.4*10^-7N. What is the charge on the graphite coated shpere? My teacher is a jerk and won't help me, even though its the first question I've asked him all year. Walk me through it if you could, people.

Would someone help in the following:- 1) draw lewis structure of odd electron molecules or atoms. 2) how to decide when there is going to be double or a co_ordinate bond? (had this doubt while trying to draw the structure of S2O3(2-)) 3) how to claculate formal charge and oxidation number in general and a co_ordinate bond is involved in particular? THANK YOU IN ADVANCE.....

Hello. I'm from Brazil, so my English isn't very good, sorry if I make a grammar mistake. I have a question about motion in a rotating plain. Actually, I can solve the question, but I'm missing a point: That's the question: There's a box in a cone. The cone has a friction coefficient of μ. The box's mass is M. The angle that the cone does with the ground is θ. The gravity field is g. The cone is spinning with a constant angular velocity. The problem asks to find the maximum speed V that the box can move (in this case, it's a circular motion) without go up, using only μ, M, θ and g. In the figure, I represented the force diagram by the perspective of a iner…

Helloo.. I have a function: (have no clue how to write a { 'group' for an equation in LaTeX.. did my best with what I could find..): [math] f(\theta) = sin^2(\theta ) \text{ when } 0 \le \theta \le \pi [/math] [math] f(\theta) = sin^2(\theta ) \text{ when } \pi < \theta \le 2\pi [/math] with values of the function given by periodicity for other domains of theta. Obtain the Fourier series expansion for f(\theta). Okay, so we've only done this once in class on the board, and it was with a completely different equation - one without 'conditions' for that matter, just periodicity (a saw-tooth function). I am having trouble doing this one. Okay…

Okay so this is probably a really easy problem, but my teacher literally doesn't teach us any thing, so can someone please help me. The coefficient of static friction between a 2.5kg box and a wooden board is .45 and the coefficient of kinetic friction between the box and the board is .28. The box is placed on the board, which is slowly lifted at one end until the box starts to slide down the board, at which point the angle theta of the board is held constant. Determine the angle theta of the board and the acceleration of the box as it slides down the board.

Like i sayed in my other posts this is probably easy but my teacher doesn't teach us anything so i don't have a clue how to do this. Can someone please explain how to do it? A window washer pushes a sponge up a vertical window at a constant speed by applying a force. The sponge has a mass of .800 kg, and the coefficient of kinetic friction between the sponge and window is u_k=0.253. Determine the magnitude of the applied force, and the magnitude of the normal force exerted by the window on the sponge. *There is a 20 degree angle

Can someone please help me. My teacher hasn't taught us anything, yet she expects us to be able to do this. A 2.00 kg box is at rest on a horizontal floor. A horizontal force of 18.0 N is required to keep the 2.00 kg box moving across the floor at constant speed. A box of unknown mass is stacked on top of the 2.00 kg box. A horizontal force of 56.0 N applied to the 2.00 kg box is required to keep both boxes moving across the floor at constant speed. What is the mass of unknown box?