Calculations Definition and 982 Threads

some antiderivatives (partial fractions, trig sub, etc) can be nightmares to compute, but I remember series solutions of differential equations being worse, especially if finding the radius of convergence is included. can anyone think of things that are worse to calculate?

Chloroform is used to extract caffeine from water.If the distribution coefficient, KD=10.What relative volume of chloroform-water should be used to extract 90% of the caffeine present in one single extraction? Now i know that KD=Co/Cw and I've solved a question on how much weight of an acid...

Can anyone recommend any books that cover k.p theory so that a beginner may be able to (eg) get a realistic programme running? Perhaps aimed at the beginning PhD stage (so will have a good background in quantum mechanics)? I find journal articles difficult to follow, and have found no...

Does anyone here have experience using VASP (especially VASP 5.2) for parallel calculations? I'm currently using ABINIT (abinip, and abinip with the "paral_kgb" variables) and although the price is right (free), it has been giving me some problems lately. The input files for VASP and ABINIT...

The Basis of this question is that: * Rockets launched at an angle follow the path of a rectangular hyperbola when thrust greater than their mass is produced. * That rockets fall in the path of a parabola when thrust is no longer produced, this only applies when the rocket has both x and y...

For a series LC circuit the Q I believe is Q= 1/R^(L/C). I have a 1.923 Henry inductor and a 4.4uF cap. The resistance in the inductor is 52.5 ohms. The answer I got was 111.86. I know the circuit can't have a Q of that value. Where did I go wrong?

Homework Statement A very silly person, intent on catching pigeons on the roof of an apartment building, trips and falls a distance of 44.6 m. She lands on a metal garbage can, crushing it to a depth of 0.422 m and walks away without having been seriously hurt. What acceleration did she...

Ok, an easy one I think? I am given an equation to work out the strain on a beam, the dimensions of the beam are in the equation (obviously) and in the question these are given in mm and cm, am I right in thinking all the measurements in the equation need to be in m and the question is trying to...

I'm designing a paddle wheel drive house boat and need to do some calculations to see if the parts I have on hand can do the job. Paddle wheels will be 6' dia. with 8 paddles by 3' long . Paddles will be 3' long by 10" and will have the tops of the paddles submerged by 2" to 3" when the...

I have a 24 KW 3 phase 120/208 volt synchronous generator I bought from China and I am having trouble finding the available short circuit amps or the %Z rating. Is there a chart anyone is aware of for common short circuit capacities?

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what are load calculations for a transformer? A 44kv line is distributed into the industry using around 8 transformers 3750kva, 2500kva and 1500kva. What does this mean and what are the load calculations for this? Also how is it distributed?

Homework Statement The specific heat of mercury is .03 cal/g C and its boiling point is 357 C. The specific heat of water is 1 cal/g C. It takes 65 calories of energy to vaporize one gram of mercury and 540*(edit) calories to vaporize 1 gram of water. If both substances begin at room...

Homework Statement I'm powering through some calculations on limiting reagents. My answers seem to be slightly off with the proper answers. I'm talking about minute differences but still differences all the same. The answer is very much well within the same ballpark. Would I lose some marks...

I have this problem and it seems like it has a simple solution, however I can't seem to figure it out. Using the following values and the previous equation calculate the rate of climb for a typical airplane at an altitude of 8000m. 4 Engines each with 150kN of thrust. Aircraft mass is...

Once again I'm going through all my old homework and taking the notes I should have done in the past, and I am stuck on calculating the components on a Bandpass filter. How would I go about this. I have the answers I just want to know how to find them. Thanks...

1.The equilibrium constant is Kc = 85.0 at 460°C for the reaction SO2(g) + NO2(g)\UpdownarrowNO(g) + SO3(g) If 2.24L SO2, 4.48 L NO2, 2.24 L NO and 3.36 L SO3 (ALL AT STP) are transferred to a 5.00 L reaction vessel and heated to 460°C, what will be the equilibrium molar concentrations? 2...

Homework Statement 2.0g of pure undiluted HsSO4 is cautiously added to water and the solution diluted to 500 cm3. What volume of 0.1M potassium hydroxide, KOH, would exactly neutralise 25cm3 of the acid solution? Homework Equations concentration = number of moles/volume mass in grams =...

What calculation is the to find the amount a helicopter (or flying device using rotor blades) can lift? I would of thought I would need to take into consideration the RPM of the blades, the size of the blades and maybe the angle. I was hoping there would be some calculation telling me how much...

I'm confused about a point concerning complex power calculations. The formula my text gives is S=V(eff)I(eff)*. I'm confused about what the conjugate is for I(eff). The way I understand it, I(eff) = I(rms) and I(rms) = I(m)/√2. Since I(m) is a real number, and I(m)/√2 is real, how is there a...

Hi Guys newbie here. Im trying to design a CHP system in which an engine with steady exhaust gas flow uses a heat exchanger to heat water for use around the home (central heating, washing water etc). The engine specifics are to be developed but i need to be able to size a heat exchanger so i...

Homework Statement Inductor 12 Henry, energy supply is Emf knot. At t=0, the switch is opened which leads to rapid discharge along a resistor. The flash from the discharge lasted 50 ms. What is the resistance of the resistor? Homework Equations I know to use i=Ie^(-R/L) t but what...

Homework Statement Need to do calculations for the jib. The jib is 600 mm long and 40 mm wide. It is attached to a base at the bottom with a pin. The cable is going through from the motor, and at the top there is a pulley. We have to lift 2 kg of weight with a motor. The jib is very...

Homework Statement 0.9966g of Iron Wire was used... Iron Wire was placed in 200cm3 of 1m Sulphuric Acid, this was heated and the hydrogen gas vented off... Producing... Fe + H2SO4 = FeSO4 + H2 Fe = Iron H2SO4 = Sulphuric Acid FeSO4 = Ferrous Sulphate H2 = Hydrogen This...

This is driving me crazy. I am calculating the order g^2 (two loops) vacuum energy in the Wess-Zumino model, and I don't get a cancellation. The tadpole diagrams cancel out but the others don't. I have checked that I get the correct results for the one-loop corrections to the scalar...

Please see circut and question at http://www.flickr.com/photos/37144556@N07/3421275866/sizes/o/ Are these calculations correct? (a)total resistance= 6.25 25/6.25= I total = 4 v=ir 4x6=20v (b)v=ir so 20/10= 2amps power=vi so 2x25=50watts? Thanks

An electric fan is running on HIGH. After fan has been running of 13.2 minutes, the LOW button is pushed. The fan slows down to 98 rad/sec in 1.83 seconds. The blades of the fan have a radius of 0.62 meters and their deceleration rate is 42.3 rad/sec2. a) What was the initial angular speed of...

I have a chemical practical coming up in a few weeks time and need help sussing out some questions. I know that the practical will be on redox titration between h2o2 and KMnO4, I wanted to know how I could determing the concentration of h2o2. Could someone run through a specimen calculation...

Hi, I'm trying to compute the equations of motion for a car as shown in the attached image. α = steering angle θ = orientation of the car relative to the world coordinate system Say you're given the linear velocity v and the steering angle α. How do you compute the position and angle...

I am designing a kayak training machine as a final year project. Basically, the design consists of a frame supporting a weighted flywheel that provides the resistance. The flywheel is mounted on a shaft through bearing units in the frame and opposite direction sprag clutches are mounted onto...

Hey, I would like to design a lightning pole to be installed on the street (or in parking lots). The height of the pole is about 1m. I would like to calculate the impact of a car heating the pole in order to evaluate the damage to the pole (and to the car). I know the car mass...

Hi I have a test next week and am currently on spring break so I don't have a teacher to ask for help, I just want to confirm that some of these answers are correct and get some help for others. 1. A line with a charge of density -2uC is on the x-axis starting at point x=1m to x=3.5m. Find its...

Ok, this is a very basic question, but for some reason my head can't work out the last bit and its making me doubt the workings... As the attached diagram shows, there is an air compressor attached to a piece of metal pipe that then has a piston on the end. The goal is to make this piston...

Homework Statement A baseball pitcher throws a ball vertically upward and catches it at the same level 4.2s later a) with what velocity did the pitcher throw the ball? Homework Equations The Attempt at a Solution I put this into givens t = 4.2 s displacement = 0 m if the...

Hello Thanks for you help, I have to design a gearbox which will be connected to an electrical motor with a 11 Kw, 960 rpm, 42 mm shaft diameter, I want the gearbox to rotate a sprocket with a diameter of 337 mm in a speed of 40 rpm, I don't know how the gearbox is to be designed for the...

My physics teacher said that our resultant answer should have the same number of sig. figs. as our uncertainty (he allows 2 sig. figs. at most); however, having done some of the problems, I get answers - when not rounded - such as 24.0 +- 0.1m, which when rounded to 1 sig. fig. results in 20 +-...

1. Homework Statement [/b] assume g = 9.81 m/s2, and friction can be ignored. A gun is fired horizontally at a target lying on the ground 188 m away, and the bullet hits the center of the target. The muzzle velocity of the gun (the speed with which it fires bullets) is 387 m/s. a) How...

EDIT: I finished the assignment other than the two problems listed here, I got 91.66/100 but would love those last 8.44 points, I'll be checking in on this topic Thursday afternoon and might have figured it out by then but I am wary to waste my last attempt. So.. that's the update Ok...

As a pendulum can be used to calculate the gravitational field strength by using the equation Time period= 2(pi) sqrt (length/g) this equation assumes that the pendulum bob is moving in Simple harmonic motion. However at very small lengths the pendulum bob tends to move in a more...

Hello, anyone knows a good article that describes the first-principles calculations please link or type the title of it, any idea what does it describes, appreciate your help. o:)42

Hi there. Came upon another tricky question in my mcat prep book.. this one makes no sense to me. https://dl-web.getdropbox.com/get/siphon.PNG?w=389b1d3a "A siphon is used to draw water from a water tower. What is the approximate maximum height d at which the siphon will be capable of...

Homework Statement A particle moves in such a way that its position z, in meters, is given as a function of time t, by the equation z = 2t^2 − 3t^3. At what times is the particle at position z = 0? (two answers; one is 6E-1) Homework Equations z = 2t^2 − 3t^3 The Attempt at a...

Hello Ive come across some approximate cross section formulas during a course of particle physics. And in a reaction like A + B --> R --> C + D the cross section should be something like \sigma = K\frac{\Gamma_R^{AB}\Gamma_R^{CD}}{(s-m_R^2)^2+m_R^2\Gamma_R^2} Where K is a constant (depending...

Chemistry Homework-- Stoichiometry: Volume and Particle Calculations This is only to check my work, and I may be updating this post with more problems. There are ten questions total, and this is NOT graded. Therefore, the help I receive goes toward my understanding, not my score. Homework...

Hi all, new here, so don't know if this is the right place. All the other places in the forum seemed like advanced stuff! Anyway, i don't understand why when calculating the partial pressure of a gas in SVP conditions, you subtract 6.28kPa from the normal atomospheric pressure of 101.1kPa...

Hi, Could somebody please explain to me how you can calculate the effects of gravity in general relativity in a practical way? (Or point me to a site where these things are explained in an understandable way) I keep trying to read articles and courses about it, but whenever it gets...

I'm not sure if this is the correct area to post, but I figure if I'm wrong it'll be moved or something. I'm working on a game and I need some help with calculating bullet trajectory. I need a formula for where the bullet will be at a certain time based off of the angle it is shot from...

[i asked this question in my blog..but i know it would be better answered here] what are the calculations of the wave lengths of a cosmological redshift? (meaning them all) i just wanted to know what precises wavelength determines which red shift.. thanks guys

Hello, I am using COMSOL (RF modul) for some time now to calculate the eigenvalues (modes) of optical fibers. So far I changed all the params from hand in the software. But it is getting anoying to change a parameter (the wavelength) and to recalculate if one wants to calculate for many...

Homework Statement a satellite is orbiting the Earth in a near-polar orbit. it's orbital height is 500km. the satellite carries a nadir-viewing push-broom scanning imaging instrument with 4 spectral bands. for each spectral band, the detector array consists of 1024 detector elements. the width...