Homework Help

1. What are the difference between relay circuit and PLC circuit? 2. What are the 4 classes of programming languages of PLC? 3. How to illustrate the meaning of control system in control and automation system? 4. How to illustrate the major role of CPU in a PLC and what is the major role of CPU? 5. How to illustrate the major role of volatile memory and non-volatile in a PLC and what is the major role of volatile memory and non-volatile? 6. An on-off controller is used to control the temperature of a process. The cycling amplitude is reduced by making the two heating rates very close to average required for normal operation. What are the disadvantages on this set up?

i need help in this question im not being able to understand how to solve this... :S

Hi, I was recently assigned an extra credit project of creating a 3D diagram of the layers of Earth. At first, this seemed like a simple task, where I could just cut out an eighth Styrofoam ball and label the inside. But, my teacher wants something original... something she hasn't seen before. This requires a bit more creativity than finding old things online, as because other people in past years have used most ideas I could find online. An example of a diagram that a student last year used, which got a perfect score, was a glass jar, with colored sand, each color representing a different layer of the Earth. He made sure each layer of sand was pro…

A chocolate ice cream cone is filled with melted chocolate ice cream of density 1.20g/cm^3 The cone is 10 cm long and has diameter of 6cm at the larger top end No a small hole of diameter 1 mm is produced at the narrow bottom part and the ice cream starts exiting out the bottom hole. Ignoring the viscosity of the melted ice cream, find the amount of time it takes the ice cream to run out through the bottom hole completely. Assume the velocity of the chocolate ice cream to be zero at the larger top end. Please help i dont know where to begin some one told me its just sqrt(2gh) but i dont know where that formula comes a derivation would be nice to know my book dosnt seem …

The Vertical cylinder vase of radius r is mounted on its center on a rotator. At rest, it is filled with liquid to a depth of height d. The vase is then rotated about its vertical axis with angular speed w. The y axis lies along the rotational axis and the origin of coordinates is at the base of the vase. A) Derive the equation that gives the intersection of the liquid surface with the x-y plane, when dynamic equilibrium is attained at some w in terms of d,r, and w B) Find the maximum w for which the bottom of the vase will still be completely covered with liquid assuming that the bottom is perfectly flat and that the vase is tall enough to no lose any liquid. We …

Hi!!! I need some help at the following exercise... Let [MATH]B[/MATH] be a typical brownian motion with μ>0 and [MATH]x[/MATH] ε [MATH]R[/MATH]. [MATH] X_{t}:=x+B_{t}[/MATH]+μt, for each [MATH]t>=0[/MATH], a brownian motion with velocity μ that starts at [MATH]x[/MATH]. For [MATH]r[/MATH] ε [MATH]R[/MATH], [MATH]T_{r}[/MATH]:=inf{[MATH]s>=0:X_{s}=r[/MATH]} and φ([MATH]r[/MATH]):=exp(-2μr). Show that [MATH]M_{t}:=[/MATH]φ[MATH](X_{t})[/MATH] for t>=0 is martingale.

Hi, So I have been given a data base of habitat connectivities and the corresponding data base for the distances between habitats. I need to convert either of these into the actual percentage of population that moved for use in Vortex. If anyone knows how to go about this help would be greatly appreciated! Thanks

Hey!!! Could you help me at the following exercise.... Consider a gamble,with the same possibility to win or to lose.If we win,we double our property,but if we lose we halve our property.Let's consider that we begin with an amount c.Which will be the mean value of our property,if we play n times(independent repetitions of the game)???

Hi, I have a physics project which I need to make my own glider but i don't know how to make. I search on the internet and I found a useful tutorial but the problem is, I cannot find a printable parts of a glider. Can someone give me a website where I can find parts of a glider so that I could just print it and bulid it? And also I need to draw a schematic diagram for it but I AM not good at drawing, can someone help me please??

Are stoichiometric calculations an effective way to predict limiting reagent and excess reagent? This is one of the questions asked from the lab report that I am doing. My problem is how to explain this, I know that it is an effective way because I got the limiting reagent in the experiment same as my calculations. But I think that's not a proper way on how to explain this. CAn someone help me please?

Goodmorning everyone! I have this problem: The mass of a given airplane at sea level (g=32.10 fps2) is 10 tons. Find its mass in lbm, slugs, and kg and its (gravitational) weight in lbf when it is travelling at a 50,000-ft elevation. The acceleration of gravity g decreases by 3.33 x 10-6 fps2 for each foot of elevation. I already know the lbm and slugs But my concern is that I can't found the answer lbf which should be 19, 850lbf My solution: F =ma = 20000lbm (32.0075ft/s^2) =640150lbm-ft/s^2 640150lbm-ft/s^2 x (1lbf/32.174lbm-ft/s^2) = 19896.5lbf But my textbook answered 19850lbf can anyone show me how the book get 19850lbf Oh I g…

One cause of reduced state of oxygen delivery to internal tissues during excessive sweating is a. increased blood viscosity b. increased blood pH c. decreased blood viscosity d. decreased blood pH The answer was A. Now I understand that during extreme sweating one would experience decreased blood volume. As such, the blood osmol would increase because you have a higher concentration of particles in a smaller volume. However, won't blood travel slower and as such there would be a chance of greater exchange of O2 for CO2 or is the concentration of O2 less in the blood as well?

I have recently conducted a biology experiment that requires me to calculate percent conjugation. The value that I obtained is very low. Why is bacterial conjugation so rare?

Could someone help me with this question its quite hard A student has a mixture of Ca(oh)2 and Cuso4. What observations will he observe when he adds each of the foloowing: 1. Water 2. Nitric Acid 3. Filter the mixture with H2SO4 4. Use this filter and add ammonia 5. Use this filter and add KI 6. Use this filter and add Fehlings Solution and place in a water bath.

Hello, I've come upon a (probably very easy) problem while writing about information theory and transmission of information, but be that as it may, I'm stuck. Since it is a rather specific area of science, I'll give a brief introduction, so maybe somebody who isn't familiar with it can help me as well. This is an excerpt that I am having trouble understanding. "For simplicity, we will assume that our source emits symbols into the channel at a rate of one per second. The transmission rate R is defined to be the average number of bits of information transmitted across the channel per second (the observant reader will note that R is nothing other than mutual …

Hi! I hope someone can help me with the following exercise... n>=1, 0=t_{0}<t_{1}<...<t_{n}, a_{1},a_{2},...,a_{n} ε R. Show that the random variable a_{1}*B(t_{1})+...+a_{n}*B(t_{n}) is normally distributed and find its mean value and variance.

Hi, I'm new to these forums and I've turned to this site out of desperation. My college Earth, Space, & Science class has a project due that I am a part of and I am having a difficult time understanding 3 of the questions that deal with precession of the Earth's axis. I understand the basis of precession in that the axis itself rotates in addition to the rotation and orbit of the Earth but I guess I don't understand it well enough because these 3 questions have me totally stumped. Even Google searchs, which usually help, have left me clueless. Here's what I'm working with: Question 1.Refer to the image below to add the path for precession to the Earth’s axis. Inclu…

I need help with my unkown project, this is my last resort. Gram reaction: negative Morphology: cocci Color on nutrient agar: cream color Motility: motile Oxygen requirements: faculative anearobe Amylase: negative Gelatinase: positive Glucose: acid/gas Lactose: negative Indole:positive Methyl red: positive Voges-proskauer: negative Citrate: positive Oxidase: negative Catalase: positive Lysine decarboxylase: negative Ornithine decarboxylase: negative Phenylalanine deaminase: positive Urea hydrolysis: positive DNase: negative Hydrogen sulfide production: positive Nitrate reductase: positive Nitrite reductase: negative ***PLEASE help!!!! I can't …

1. The problem statement, all variables and given/known data 2. Relevant equations In question. 3. The attempt at a solution To be clear it's part (vi) that's unclear to me. In order to ignore the cosine term it has to reduce to 1. This can happen, only if k(x1+x2)/2 = ωt Is this a correct assumption ? Also, it is known that k = 2∏/λ and ω=2∏/T However, I'm trying to think in what way these two components could be equal but I can't get it. Could someone give me some help, please ?

Hi everyone I need to write about a current event article that is related to my micriobiology course. The article I found is about food posioning: http://www.cnn.com/2013/04/23/health/foodborne-illness/index.html Now that I have my article I need to formulate two questions that I will then do further research on to answer. My question is what two questions can I use to formulate a good responses using research?

Hi all I'm researching how light rare earth elements - specifically neodymium - is processed. If anyone can help explain to me how the purification process works (if you use really complex terms could you please just give a brief definition) as well as providing chemical equations, I would really appreciate it. And if not, if you know some good links or articles that do explain it, please let me know of them as well. Thanks

Alright so I have been posting these questions up on a whole bunch of forums and no one seems to be answering any of the questions I have posted up, so it would be much appreciated if someone where to help me out with the following questions, because I feel they are easier then they seem but I just over analyze things. Any help on the following questions will be appreciated. Thanks in advance 1. Use the initial pH of the acetic acid solution to find the initial [H3O+] and initial [CH3COO]-(2) Initial pH = 2.58 2. Assume that the amount of CH3COOH that ionizes is small compared with the initial concentration of the acid. Calculate Ka fo…

you can go to this pic(link): http://imageshack.us/photo/my-images/854/scan0002fh.jpg/ In Green Circle: why is K = V^2/2k? and what is the small k? is it kinetic energy? In Red Circle: what is 778? how 778 appear in this problem? in Black circle: why is Work=pv? thx in advanced just explain even if it just one question you can answer Godbless

I am doing a titration for school between sodium hydroxide and vinegar. I have no idea what the equation might be so I completely guessed. I was wondering if someone could help me by telling if it's right or not the reaction equation is: CH3CO2H + NaOH --> NaCH3 + CO2 + H2O If it is not correct can someone please tell why and how I may be able to improve it? Thanks a lot

Hey guys, I have trouble grasping Quantum Mechanics...not such a rare condition, I guess I just need a nudge in the right direction, I seem to know the basics but somehow when I try and solve the homework we are given I get stuck and unsure on where to begin. Let P be an operator that commutates with the Hamiltonian HP=PH show that if |phi> is an eigenvector of H, P|phi> is also an eigenvector of H with the same eigenvalue. Thanks in advance!