Machine Definition and 968 Threads

Homework Statement Explain how the synchronous machine stator current can be varied if the load is constant. Justify your answer with phasor diagrams. 2. The attempt at a solution If load is constant then load angle, the angle between induced e.m.f. and terminal voltage remains the same...

edit: turned out to be a calculator typo...mods feel free to delete this thread if you wish, I won't complain. Homework Statement [/B] Having issues with part a) imgur link: http://i.imgur.com/4hzLyhb.jpg Homework Equations Resistivity of muscle (from table in text): \rho \approx 13...

Homework Statement I studied that a larger air gap in alternators aids in sinusoidal mmf distribution ..I didn't get this as larger air gap should deteriorate the wave..but here it is opposite..?? Is it right ?? [/B]Homework EquationsThe Attempt at a Solution One point can be said that larger...

I've read a couple other threads about this issue. And one even addressed my exact question but the answer didn't help me understand this at all. In an Atwood machine, why isn't the total force on a mass = its gravity minus the gravity of the mass on the other side? I keep seeing tension in...

Hi, Say you wanted to have a generator or motor stay at near 90degrees for maximum torque while generating or motoring, over various loads or over various supply frequencies. I assume there is some established method of controlling this (varying the rotor resistance with feedback perhaps?) does...

Hello all! I work for a machine design & manufacturing firm. We also do machine repairs & refurbishing work. We currently have taken up a project where-in an we have to solve a critical problem in an automatic part washing machine. The machine is a multi-stage concept, wherein the parts are...

i need help. My hydraulic press machine just go up but won't come down. anyone know why?

Homework Statement I know it's not directly related to engineering, but its from an engineering economics course! Homework EquationsThe Attempt at a Solution Hello, I'm trying to solve this problem, and my first thought it to find the present value of each machine $$ PV =...

Homework Statement A gun is fired from a 200 meter cliff 200 meters away from an Atwood's Machine that is also suspended 200 meters in the air with a monkey of 20kg on the ground and a second unknown mass pulling the first mass up. Find the mass of the unknown needed for the bullet and the...

I have an Atwood Machine. I have an aluminium Pulley of radius 4 inch. A gym cable running over it. Not sure coefficient of friction but smooth movement. One end of rope, I attach wt. of 0.5 kg. I had to attach weight of 1 kg for acceleration to start. If I attach 2 kg, I had to attach 3.1 kg...

Hi, So we're doing this Lab on Transient reactance of a synch generator and I'm reading Sarma's classic: Electric Machines Steady-state theory and Dynamic performance p. 474-479 But I can't see how to get the actual exponential time constants for the sub-transient and transient reactances? Thanks

Homework Statement A pumpkin and a weight are attached to a frictionless pulley. As the 5kg weight is released, the pumpkin accelerates down at 4.65 m/s^2 to the ground. What is the mass of the pumpkin? [/B]Homework Equations How do I find the mass? The Attempt at a Solution T=m1g ma=m2g-T...

Homework Statement [/B] Consider a half-atwood machine on a cart as below, with mass m_2 attached to M via a frictionless track that keeps it pinned to M but allows it to move vertically. All surfaces (except between the wheels/ground) are frictionless, and the pulley and rope are massless. If...

Hi, I'm trying to understand the physics on a Scrambler; and am having difficulty with balance of torques equation. In below image a vehicle is moving to the right while breaks are applied. The balance of torque is defined as: h * F1 + h * F2 + b * N1 = (B-b) * N2 I understand the...

Homework Statement So I'm working on question five from my book. [/B] The book references a earlier problem, which you'll find below for further reviewing purposes. Homework EquationsThe Attempt at a Solution I apologize for posting the question as a picture. But given my situation, it...

I started looking into the operation of a really simple machine called the "Herodotus Machine". A quick Google search gives some good info on it https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=Herodotus+Machine . I wanted to use a block that was taller than it was...

Aloha, I'm new here and stumbled across this site in my attempt to salvage a whirlpool washer motor to repurpose as a motor to grind barley to make my beer. Until now, I just used a hand crank and decided it's time to modernize. I just salvaged a nice looking, 3 speed, 1/2 hp motor from a...

Homework Statement The double Atwood machine has frictionless, massless pulleys and cords. Determine (a) the acceleration of masses ma, mb, and mc, and (b) the tensions Fta and Ftc in the cords. Homework Equations F=ma The Attempt at a Solution So I drew free body diagrams for the mass A...

In slip test, we provide a constant 3 phase voltage across the stator of the machine. Then why does that voltage vary? Its like a variable inductor circuit due to different air gap length but basically if the voltage impressed is kept constant, why does the voltmeter show variation? Is it like...

Homework Statement I still don't got the hang on Atwood Machines, and i don't know if I am wrong here or just overthinking it. But i got this one exercise where i am kind of stuck in two of the sub-exercises. So I am hoping there is someone here who could guide me in the right direction.Atwood...

Hello the proof of the Spiser's book (introduction to theory of computation): PROOF We let R be a TM that decides REGULARTM and construct TM S to decide ATM. Then S works in the following manner. S = "On input (M, w), where M is a TM and w is a string: 1...

I know that the centripetal force is the resultant force which points to the center. So in the case of a washing machine, what force pushes the clothes and water to the outer edge? There is not centrifugal force, but then how come all the clothes appear to get pushed to the circumference of the...

What are the odds that humans will come up with a 100% (or extremely close to) efficient machine within the next couple centuries. If so, what principle do you think it would work on? How about a perpetual motion machine? Share your thoughts.

Hi I am creating a slot machine application and am having a lot of trouble calculating the probability of Four of a Kind, Five of a Kind and Six of a Kind for each Position TYPE (A,B,C,D,E,F,G,H) All of the positions are fixed and remain in the order that can be seen in the above image. The...

Are self-replicating machines still theoretical or have demonstration models (other than the rip rap 3d printer)been produced?

Hello. I'm wondering why my approach to solving this problem (Morin 3.2) is faulty. Homework Statement A double Atwood's machine is shown, with masses ##m_1##, ##m_2##, and ##m_3##. Find the accelerations of the masses. Homework Equations ##F = ma## The Attempt at a Solution Let's say the...

I know perpetual motion is by no means possible, but I want to make something self powered, in the same sense. I don't have too many resources, but I am looking to make something whose own excitation would power the machine, for say, an hour. I.e. pushing a button that would cause something to...

I've seen the electrostatic generators as a student but never had a chance to operated one. So I built one. A small one using compact disks. Now I am in the process of building a larger one, using two 12 inch disks cut from acrylic. I've got the completed disks (32 sectors each), base...

Homework Statement When a force of 2 lb is applied to the handles of the brad squeezer, it pulls in the smooth rod AB. Determine the force P exerted on each of the smooth brads at C and D Homework Equations ##\sum F_x=0## ##\sum M=0## ##\sum F_y=0## The Attempt at a Solution I drew a free...

Hi everybody, I've been trying to find instructions on how to build an electric washing machine but am not having any luck! I found non-electric manual operated makeshift washers, but I need something with a little more oomph! The closest thing I've found is someone made a power saw from a...

We are working on a machine component structure that weighs around 500 kg.This component is fixed inside the train on top roof using 6 bolts..Now the part is we need to design bolt size and no of bolts under worst condition..The acceleration of train may be taken as 0.3g,where g-accn due to...

Homework Statement Given m_1 on an Atwood's Machine, what is the mass of m_2?Homework Equations a_{net1} = \frac{m_{1}-m_{2}}{m_{1}+m_{2}}gThe Attempt at a Solutiona_{net1} = \frac{m_{1}-x}{m_{1}+x}g \frac{a}{g} = \frac { m_{1} - x } { m_{1}+x } \frac {a}{g}m_{1} + \frac{a}{g}x - m_{1} =...

HI everyone. I was just wondering about a career in the IT (I study communication systems engineering, but I'm rather interested in coding, rather than Internet and communcation systems- related stuff). I wanted to ask you, given the advances that technology is making, which skills would be...

Homework Statement The book says that "the induced voltage E_a can be found by measuring the open circuit voltage at the armature terminals" Homework EquationsThe Attempt at a Solution But isn't there a voltage drop across the resistor so that they can't be equal? or is this ignored

Hi everyone. By reading stuff on the Internet, I found many times the correlation between machine learning and NMR, or, better, algorithms that are implemented for that kind of technology( The same goes for PET, or CT scans. The thing I want to ask is, how much do you think that the two things...

Hey! :o I have to show that a set is recursive if and only if the set and its complement is recursively enumerable. I have done the following: $\Rightarrow$ Let $A$ the recursive set, so there is a Turing machine $M$ that decides the set $A$. We construct a TM $M'$ that semi-decides the set...

Hi everyone. I was just reading stuff about carreers like "data analyst" or "machine learning jobs", and I found out, by reading various sites, that machine learning people (especially those with CS or stat background) is, and will be, a good opportunity of working, there'll be much jobs in that...

Hi guys, I wanted to ask something that I am interested on Which is on the traditional sewing machine mechanical mechanism (On the foot paddle part) Image taken from Google. From the image above, a typical sewing machine For such application, what is the "Name" for it? Im more likely wanted...

Homework Statement The robot crawler has a magnet attached to it. The idea is to get the crawler up the wall. What is the magnetic force required to hold a object (in this case) a robot crawler with an attached Magnet? Is more magnetic force required to hold the crawler while it goes up the...

synchronous machine can run at synchronous speed but why can't induction machine run at synchronous speed?

I work with a company that buys and sells millions of trading cards every year but the majority of these are sold for fractions of a penny if they're sold at all. From what I can see there are two options for this company to get more out of these cards, both of which are incredibly...

in a parallel operation of synchronous generators...while synchronising a new generator to a bus..why the speed of incoming generator should be slightly more than the other generators that are connected to the bus?

Homework Statement You have a unknown Transformation machine T. that transforms from R^4 --> R^3 Vectors U and V are known and the output from T is also known. Can You calculate the values of T? Homework Equations [/B] What values/information is needed to calcuate T ?The Attempt at a...

Homework Statement Please see attached for diagram. We know that the elevator arm is horizontal when the lift is stationary, with ## M_{1}=\frac{4M_{2}M_{3}}{(M_{2}+M_{3})}## It wants us to find out if this is still the case when the lift is accelerated upwards at a constant velocity ##g##...

Hello, I am trying to build a personal (one-manned) propulsion system that will allow individuals to fly above the trees, preferably fast, and for long amounts of time. I plan to do so using propellers. The power will need to be plentiful and long lasting. These are some options that I am...

Hey all, I have been put in charge of developing my company's research and development "lab" and I am currently looking for some testing equipment to buy. My background is in civil engineering, however I did do a small amount of material testing in school, and I'm familiar with the concepts...

Hi, My name is Vitaly, and I'm a visual effects artist and filmmaker. I'm planning to shoot a sci-fi short film, in the end of this April. The logline goes like this: A scientist must send a warning message through time before he gets killed by an assault team. It's going to be an intense...

I have bought a washing machine on sale. It is rated at: Its gross weight with clothes and water=100kg, At least 50kg of the machine's weight is due to concrete blocks attached to the inner drum. Max Centrifuging Speed=1400rpm, Max Clothes load=7kg. It dances(when taken for a spin, that is.)...

Homework Statement A “pedagogical machine” is illustrated in the sketch (attached image). All surfaces are frictionless. What force ##F## must be applied to ##M_1## to keep ##M_3## from rising or falling? Homework Equations $$\sum_{}^{} \vec{F} = m \vec{a}$$ The Attempt at a Solution I...

building a small portable crane to be used on a small boat that will be used to retrieve a sediment grab (weight = 200lb) at a depth of 50m