Machines Definition and 209 Threads

Suppose i build a time machine , then go back in the past & kill myself . I die the instant i kill my past , but how in the first place i built the time machine ?

is it possible to produce a centafuges machines? how many RPM does the cetrafuge have to rotate for the separation to occur?

Using a Van De Graaff (VDG) machine, we can easily generate million-volt high voltage. The high potential difference can be generated effectively with minimum energy supplied to the machine. The larger the volume of the machine would be, the higher the voltage could get. However, stability...

What initially attracted me to this book was how easy it was to read, or atleast how easy it said it was to read... I have read the first few pages and I am really enjoying it. For anyone that has read it, I would like to know if any of it is dated. It was published in 1999, or that is the case...

looking to design and hopefully build a micro-tensile tester to test the properties of human hair. as part of my uni class I need to design the grippers involved and have a look at non contact extensiometers. Could anyone point me in the right direction with some links or books? or even...

[SOLVED] Simple Machines Proble, Homework Statement Two kids are riding on a seesaw that is 3.0m long with its fulcrum exactly in the middle. When one end touches the ground, the other end is 1.4m in the air. If one child has a mass of 20.0kg and the other is 28.0kg, which child sits at the...

hey In its most basic form virtualization creates computing power from existing machines. In the process of creating additional resource it uses - i would imagine a vanishingly small amount of energy, is this a reasonable assumption? If so how is virtulization described in terms of...

This may be a bit vague, as I don't remember all the details. When proving Turing's halting problem, at some point you will say something along the lines of, "given a list of all Turing Machines, assume that there exists a Turing Machine M which decides whether machine A halts on input B". The...

I don't get why do we use Flip Flops for Finite State Machines? Can anyone explain? -Thankyou

[SOLVED] Machines Problem Homework Statement A ramp, 18m long and 4.5m high is set up in order to wheel a 25-kg box at a constant speed. Assume that by wheeling it there is no friction. Homework Equations IMA= \frac{d_{in}}{d_{out}} The Attempt at a Solution I know this is a...

Hey guys Im having problems figuring out this Statics question I feel like I can solve it, But it has been bugging me for weeks Here it is. and Here is a quick FBD and notes I posted from others Would Anyone let me know If the FBD is correct? Im not asking for the answer. I honestly just...

Hi, I am taking a Power Devices and Systems course and I am looking for a good textbook. The type of circuits/machines we are covering are: Power circuits; transformers; magnetic circuits; three phase connections; single phase motors; polyphase machines; synchronous generators and motors...

I am looking for a book on electrical machines. I am particularly interested in one which would described the behaviour of the magnetic field inside the machine during various operating conditions like no load short circuit etc. can you recommend a book or a website which would describe it I...

Does anyone have any good ideas and designs of a gravitational machine. I have one, but I still need to study some other things before I start experimenting on the subject.

Does anyone have any good ideas and designs of such a machine. I have one, but I still need to study some other things before I start experimenting on the subject.

Do any of you know of a good site, or just a general site, where physics is applied to pinball machines? I 'm having trouble finding any, if there are any out there, that is.

If there was a machine that claimed to have all the characteristics of such a machine and relied on gravity, can it be called a perpetual machine?

If there was a machine that claimed to have all the characteristics of such a machine and relied on gravity, can it be called a perpetual machine?

I found how to make a perpetual motion machine! (just joking, keep reading! :-p) We just saw what they are in my thermodynamics class, and if I understood correctly, it represents the only heat-to-work conversion machine not (theoretically) in violation of the second law. And this solution is...

Hello Guys, I am a beginner in the field of Electrical well i have certain queries to ask from u genius guys 1):WHY THERE IS NO BACK EMF in 3-phase INDUCTION MOTOR 2):WHY WE REMOVE RHEOSTAT after 3-5 seconds of STATRTING OF 3-pahse INDUCTION MOTOR. 3):IF WE APPLY SINGLE PHASE ,THEN HOW...

Hi, I've been doing some reading on electrostatic influence machines like this one here called Nicholson's Doubler: [PLAIN]www.coe.ufrj.br/~acmq/nicholson.html[/URL] I was wondering if there is any drag force or back attraction/repulsion torques that the rotating disks would experience...

These are machines that I just learned about while I was bored. So, i will now ask about what looks like a triangular toothpick ion engine. So these lifters are really strange, I don't know how they work, http://www.americanantigravity.com/articles/256/1/Lifter-Plans here they are...

Finite state machines :( Okay, I'm having trouble understanding a finite state machine example in my book. It's a state table for the machine M = (S, \ell , \wp , v , \omega ) where S = {S0, S1, S2}, \ell = \omega = {0,1}. Please check out the attachment:smile: What i don't...

This is probably a simple question with a simple explanation... I understand that a 3 phase induction machine generates a rotating magnetic field in the stator which by Lenz’s law induces an electromagnetic force in the rotor which moves the rotor in the same direction as the stator magnetic...

So what happens when you give a vending machine $10 for a $1.25 soda? Does it give you $8.75 in quarters??! I've always wondered...

Hello Many people heard about aproaches for time machines. Particularly I'd like to discuss Stephen Hawking's thought, that a time machine is impossible because otherwise we would have tourists from the future, unless we can't go back to time before a time machine was made. I think everyone...

Hey, this might've been discussed here billions of times, but it fascinates me so I thought of bringing it up. If you'd ask from a person on a street that what is the difference between you and a computer ? You would probably get answered "I think, computer doesn't". It has been proven that...

Sorry if this is a wrong place to post this. What does it mean that a turing machine M recognize language A? Does it mean that A={w|M accepts w}? Is so then how does M accept w? Does it accept w if it ends in accept state?

what is your knowledge about carbon ions? is there a machine that determines its creature?

https://www.physicsforums.com/showthread.php?t=98589" my webcam is being silly. its acting like a 2 yr old and freaking out whenever it can't see me. now, I'm sure there must be some logical physics related reason why... I'm not sure what, (feel free to inform me if you know..) but there...

I heard something about electrostimulators and ultrasound thingys that athletes can use over their sprains and alike that will help them heal faster. Sounds like quackery to me, but what is it about?

Released last friday: http://www.bradblog.com/Docs/GAOReport_ElectionSecurity_102105.pdf (don't be fooled by the link name, it's the real report.) This is being discussed all over the progressive websites. The GAO is non partisan, lending bipartisan support to concerns that (from the...

The problem is stated in the picture. And I drew the FBDs of the top half of the bolt cutter, as shown in the second page: Setting moment about A to be 0, I obtain -Q(1 in)-FBy*4 in=0 And By= -Q/4 lb Then setting moment about C to be zero. I obtain FBy(0.5 in)-20 in(75 lb)=0 Substitute in By...

Are just like machiens, when they go wrong they overheat and leak fluids, the only difference is machiens need tools and spare parts to fix, humans just need chemicals :smile: oh, and some one to tell them what to do

Hi, We have two Linux servers (Redhat 9.0) 40 miles apart. We want to connect them to each other so that we can change our database settings and PHP files on them. In windows we just dial one of them from the other one and use a remote desktop. What should we do when we are using linux?

I Hope I Posted This Question In The Right Thread... By All Means, Is There Any Possibility Leading To The Development Of Perpetual Machines? Tnx Pf Folks...

I'm looking for info/help/cct diagrams on ECG machines, how they work etc etc. the full works. Looking to make a "simple" wireless ecg on bluetooth/rf. any help? sites? thanks:)

I've recently drawn up several machines that handle food. However I wanted to know if there are any materials that I should stay away from, for handling food. To clarify, I would like to go to a harware store to pick up supplies, but is it ok to run liquids or store food in pvc for example...

GR allows for the possibility of travel in time by the space-dragging effect of an infinitely long, dense, rotating cylinder. Q: Why does the cylinder have to be infinitely long? A: It doesn't, an extremely long cylinder will do - long enough to eliminate "edge effects". Q: Why even...

Lifting bodies and flying saucers, are they aerodynamic or have properties that are worth pursuing?

Here's the problem: "The bone rongeur shown [refer to attachment] is used in surgical procedures to cut small bones. Determine the magnitude of the forces exerted on the bone at E when two 25-lb forces are applied as shown." I understand that this "machine" can be broken into 4 free-body...

"Godlike Massively Intelligent Machines" On Coast to Coast tonight: http://www.coasttocoastam.com http://www.cs.usu.edu/~degaris/ A quote from the show

I wonder that are there anyone who have an idea about ball throwing machines(tennis ball throwing machine, volleyball throwing machine etc.) How can i get information about this subject? (i am sorry of my bad english, i wish i could explain what i want to learn :smile: )

there is something I want to know... Some xerox machines are equipped with these special devices to produce enlarged and redced copies of a text. WHat are these devices and how do they work?

Dear . . . Physics Forum May I Ask Some Help ? I need a website that makes me learn more about : 1. Arc Welding Machines . 2. Arc Welding Technology . 3. Welding Rodes Specifications . 4. The Calculations That We Need For How Deciding The Welding Rode Diameter Depending On The Working...

Hi, I'm new to the subject of AI, but I find it to be very intrigueing. I think I've read many times now that both the Turing Test and its variants (like the inverted Turing) have been completely abandoned as criteria to talk about AI. (They're taking some kind of immature mimesis of human...

By this I mean machines that put more energy out than is put in. Is it possible?

Can someone provide me with a good source that explains finite state machines well? I'm having trouble understanding Mealy and Moore Machines...

Hey guys, I am workin on some stuff dealin with machines at the moment but can't really figure it out. Seems simple but the book just doesn't help. If you have an object of 1000 N being pulled 5m upwards by a pully, and 20.0m of rope is pulled, then how do you figure out the Effort Force? I...

http://www.cnn.com/2004/US/Midwest/03/19/coin.operated.test.ap/index.html In this small town, breath testing machines will be installed in the two local bars to ensure customers are not drinking and driving. WHAT A GREAT IDEA! Makes you wonder why no one thought of it till now. Perhaps it...