Machines Definition and 204 Threads

can you perhaps explain in technical detail?

Why don't they mandate that all voting machines use open source software. They seem to use PC's presumedly with the windows OS. To me this is a perfect cheating machine. You give your vote to the programmer and then it is all up to him or her. There are no tests that can be...

I'm interested in learning about how original gear cutters were made, such as Polhem's manually operated gear-cutting machine or Whitworth's design. So far, I have only been able to find very brief or vague description on how they worked. Any helpful resources that explain the mathematics and...

Based on a force inputed in a machine, how do you calculate the force outputed? I would have thought you could do this with a simple torque balance but this does not always appear to be the case. For example in the case of an accelerating bicycle, the force applied to the rear gear is Ft, but...

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.

Just a random thought today: Our worn clothes are dirty. They have sweat, food stains, dirt, and fecal matter (undies). We shove these in the laundry machine, where those clothes touch the center spinner thing and the sides of the laundry machine. Even on high wash load, the water doesn't...

In the proof of Clausius inequality ##\oint\frac{\delta Q}{T}<0## for an irreversible cycle, I always find the fact that the thermal efficiency of an irreversible machine is **stricly less** than the thermal efficiency of a reversible machine, both operating between temperatures ##T_H## and...

Homework Statement The handheld press is useful for such tasks as squeezing rivets or punching holes. What force P is applied to the sheet metal at E for the 64-N forces applied to the handles? Homework EquationsThe Attempt at a Solution Not sure how to get this one started, i initially took...

I can't get over how cool/creepy this is. Researchers took image recognition neural networks and asked them to look for certain images in random noise and once identified modify the image to highlight the pattern. That new image is fed back into the machine and it's asked to do the same again...

Please help me, this is my last hope. I am an el. engineer student and i need GOOD books on electrical machinery. My proffesor is more a good repairman than a great scientist who could teach me about all the theoretical (matematical and physical) concepts which have led to modern design process...

Hi, I am an EE student that has been helping in my professor's lab. We have a Double Fed Induction Generator set up and it is rotated by a DC motor. It is used for experiments. We have the whole set up running through a controller with a graphical user interface where you can adjust various...

Hello. I have read a little about time machines and going back in time, and whether that is considered possible according to modern physics. [mentor's note - some additional text not relevant to the physical question has been removed]

It is a cylindrical ac machine. If we want to produce a sinusoidal voltage, we need B (magnetic density) to vary sinusoidally. To get B vary sinusoidally, we need to get H(magnetic intensity) to vary sinusoidally. To get H vary sinusoidal, the best way is to vary the numbers in the air gap...

We see always in source meter machines a LED which indicates the limit current. I want to know what is the limit current and what is the relationship between this later and the resistivity.

Topics covered include links, mechanisms, Kinematics of rigid bodies : Relative Velocity and Acceleration method, Instantaneous Centre Method, Dynamics of Rigid Links, Gears, Cams etc I cuurently have this book : http://www.amazon.com/dp/0195154525/?tag=pfamazon01-20 and find it very difficult...

We know that all machines or devices working on AC have high value of time constant so that there is n damage to inductor while current reversal & high value of time constant means increase in time to reach steady state as we can see in fans , coolers , etc. but the tube-lights also have a...

Homework Statement Hello ! I'm making a simple electric motor. Using copper wires and 1.5V battery. 2 magnets, 2 thumbtacks, 1 block of wood, 2 paper clips, and approximately 2m of insulated copper wire. -The diameter of the loop must be 1" CAN'T use other materials, only the above listed...

Hi, Any good and detailed book on hydraulics and hydraulic machines ? Much grateful Need to cover topics on Water Turbine, Flow through Pipes and Head Losses with detail derivations.

can a black hole be connected with the making of a time machine ?

How do you show that every polynomial-time turing machine has a family of equivalent polynomial-sized circuits?

Why is one Tension Negative and the Other Positive -- Atwood Machines Hello, Please consider the following: I am trying to understand how to solve for acceleration when dealing with Atwood machines. I keep getting hung up on one part: the direction of tension. In the image above, why is...

I've been at this problem for a good hour now and I just can't figure it out :bugeye: Please help me think through this! It is a very difficult problem in my opinion. Or maybe I'm just missing a fundamental point...Thanks in advance...

Increasing the incline on a belt type running machine increases the expenditure of energy of the runner. However the runner is not increasing his/her potential energy in the gravitational field. The only change appears to be in the manner the leg joints and muscles bend, flex, stretch and...

Hello, Budding entrepreneur here looking for help. I've had this doubt for a long time. I can read the pump performance curves with respect to Head & Q. So if I have to select a pump that gives me 200 LPM @ 10 bar pressure, how do I select a pump from the curves. Is selecting a pump that...

Hello all; I have been thinking about something for some time and could not find it through the internet so i decided to ask this to you. In theory of machines course, there is lambda (degree of freedom of space) in the degree of freedom of mechanism formula. As you already know...

Hi All, Today I conducted a lab in which we plotted the open circuit voltage (V[oc]) and closed circuit current (I[sc]) versus the excitation current in the rotor (I[x]). From the data (plots are attached to thread), it can be seen that saturation occurs in the V[oc] versus I[x] curve...

I am looking at building a machine that roams underwater, most always completely submerged. I would like at one point for the device to return to the surface and was wondering if it is possible to use electrolysis to turn the water into gas enough to provide buoyancy that would lift the machine...

Can someone explain to me, one with extremely limited knowledge of the concept of Turing Machines, what these hypothetical machines help us understand or accomplish in computer science?

Hello. I am learning about tension in Atwood machines( ideal pulley, frictionless mass, etc.) and I am having trouble grasping the concept of tension. I thought that the tension in a rope should be equal to the net force on both masses. That way the forces are balanced out and the masses are...

the lesson of electric machines and drivers -- transformer questions question: the data of a single phase transformer are as following; nominal primary voltage U1n= 230V nominal secondary voltage U2m= 12V line frequency f= 50 Hz apparent power S=50 VA loading...

Although this question is more theoretical than most of the threads in this rubric, it still seems to me to fit the description "Computer Science". If I am wrong, perhaps someone would tell me where the question belongs. The question is as follows: After reading the descriptions of...

I hear they emit radiation which deionizes atoms. Is this due to the frequency of the x-ray? Is x-ray light considered radiation?

Hey guys - I just posted another question, but I was thinking I'd like to have a better understanding of simple physics and machines. For example, I was trying to find out what simple machine is used on a masons jar (where you have spring tension, and a oblong arc, that holds it down and...

My question is probably simple answer but google and everybody else I've asked didn't know. Because of friction there can be no ideal simple machines even with like a magnetic incline plane. But if you Quantum trapped a superconductor onto a track inside of a vacuum and just pulled on it would...

This was a theoretical / rhetorical question posed by the professor during class. He hinted that this will be on the next quiz. I think I know the answer, but can you guys verify it for me? Homework Statement Why do we not perform the Open Circuit Test and Short Circuit Test one after...

hello, i am an undergraduate student pursuing engineering. kindly suggest me a good book on electrical machines (induction motors, dc motors ,etc) so that they can be understood very easily . please suggest as fast as possible :cool:

Hi guys I would like to know, what are the basic mechanical components in modern machines? I am not referring to bolts, fasteners or gears, I'm more asking in a level of differentials in automobiles, power shaft, so on so forth. because I am sure automobiles,aircrafts, missiles...

why in electrical machines we says that magnetic field transfer energy in air gap but isn't there electric field also in air gap !

If airplanes' highest speed depends directly on the air it is moving through and not the ground, does it mean we can build a time machine if only the air moves near the speed of light?

Hi, when a perment magnet machine is designed for a particular power but is operated at a much lower power, is it inefficient as with induction machines? Thanks

I have to study certain topics related to electro-mechanical energy conversion machines, AC/DC machines etc (like transformers, motors, generators and stuff). It would be great if you could suggest some good books on those topics especially ones which have got the things easily understandable...

Hello All, on paper machine which I work we have such configurations as is showed on the sketch: http://imageshack.us/photo/my-images/706/systemt.jpg/ a forming fabric (wire) is driven by two rolls, couch roll (with two suctions chamber) and so called FDR (forward drive roll). On the...

Homework Statement I have a question regarding undecidable languages. Let L1 = { M | M is an encoding of a Turing machine that accepts any input} and L2 = { M | M is an Turing machine with at most 100 states}. Is L1 intersect L2 decidable? Homework Equations The Attempt at a...

I am in the market for a soda machine and/or pop machine. I drink diet cola and my wife drinks Perrier (though I may switch to straight soda). We're figuring it would be cost effective as well as more convenient to get our own machine - if they work. Does anyone have any experience or...

I recently went to a "party" where the host was offering skin care products to buy. In order to figure out what you need you were advised to use this SAM or Skin Analysis Machine. It looked like a football replay box. You put your head under a cover and looked into this mirror. A black light...

Dear Forum, in the case of ideal simple machines the input work is exactly ideal to the output work. The efficiency is 100%. In some cases the input power is equal to the output power, but not always: when we push a box up an inclined plane we need a smaller force for a longer distance...

I am currently doing a Degree in Mechanical Engineering...currently i am doing lectures on Mechanics of Machines can some one tell me the name of any good books.

Homework Statement Assume that the pin joints at A,E, and F, are attached to the rest of the truck body, which is not shown. If a 8-kN weight is concentrated on the fork as shown, find the forces that the pins on member CDE experience. All joints can be modeled as pins. The Attempt at a...

The recession put people out of work, but when the recession weakens, there will be a huge incentive to replace what used to be workers with robots and IT. People who learned skills and worked for decades won't be getting their jobs back since those jobs won't exist. What are your thoughts on...

Homework Statement A screw jack that is used on cars whenever tyres are changed by the owner. The screw moves though a distance equal to its pitch whenever the effort lever ( jack handle) is given a complete turn. If the length of the jack handle is 24cm, the pitch is 2mm and the jack is...