Machine Definition and 918 Threads

Right upfront: I'm a noob at this. How can I find a Craigslist ad that has expired? I tried the Wayback machine, it didn't have it in the archives. Any ideas?

Homework Statement Board AB is fixed to the wall through 6 screws as described in the drawing. Beams CD and DE are connected to the board by joints at points C, D, E. At point D acts a vertical force of 7500 [N]. Calculate: A) The reaction forces at joints C, E. B) Describe the external...

Dixie Cup dispensers. How does this machine work?!? Ok, it's definitely not magical (just wrote that to get your attention), but checkout this machine: How does this machine separate one cup from the rest of the stack? Can you think of a simple mechanism to do the same thing? I'm very...

Ok so i am aware that if someone manages to travel faster than light, they are technically "travelling through time" but i was wondering if there was a way to travel backwards in time, i tried searching the web but haven't found anything so i was wondering if someone could explain it to me, also...

Homework Statement Can anyone explain to me how is the left-sided drawing related to the right sided drawing? I asked the teacher but he confused me so I let it go. http://img443.imageshack.us/img443/3036/drawinge.jpg The description is this: This crane in the drawing is designed...

conflict: why synchronous machine doesn't produce induced EMF in the DC field wires Isn't it current path through winding which produce magnetic field (rotating) the must produce EMF in the dc winding of field (same theory of induction) but why isn't true in synchronous

Homework Statement Homework Equations F = ma The Attempt at a Solution I'm completely unsure as to what the horizontal reaction force on m1 actually is. Any horizontal reaction force coming from m3 being constrained to be in between the two sides of m1 as shown will not cause m1 to...

Homework Statement Homework Equations F = ma The Attempt at a Solution What we want is for m2 to be at rest relative to m1 because this implies m2 will not be sliding across the surface of m2 and this immediately implies m3 must be at rest in the vertical direction (in the lab...

Project: Weighing machine based on potentiometer Principle: On changing the length of the wire current in the circuit will change which will change the deflection in the ammeter Set up: On top of four or three spring(same spring constant) a board is attached so when a weight is kept on top...

Here in the US midwest we've been having a drought lately, and it got me thinking of ways that we might be able to generate water more efficiently. Right now we're pumping an enormous amount of water out of the Ogallala Aquifer, beyond the replacement rate even in a rainy year I think. My...

Hey! Happy New Year 2013 to all of you! I am in good mood for learning something new so I need advice. I'm currently watching the videos for Machine learning from Stanford University, but I'm stuck at Lagrangian multipliers and duality. I got solid background in Calculus I and II (I read...

Homework Statement Figure 5-47 shows Atwood's machine, in which two containers are connected by a cord (of negligible mass) passing over a frictionless pulley (also of negligible mass). At time t = 0, container 1 has mass 1.30 kg and container 2 has mass 2.80 kg, but container 1 is losing...

Homework Statement The question is from a lab. The lab used an Atwood Machine with two masses suspended string looped over a pulley. The time for one mass to reach the ground was measured and acceleration of the mass was calculated. The results were plotted on a graph of weight difference...

I have the code. program star implicit none real (kind=8) :: x integer :: i dt=0.001 pi=4*(atan1.0) do i=1, Nsteps t = n*dt !calculate acceleration ax= ay=... !calculate values at next step vy=vy+ay*dt vx=vx+ax*dt x=x+vx*dt y=y+vy*dt end do...

Why is it that the air gap flux density is flat topped at no load. What happens to it's shape when machine is loaded?

Hi, call me [SIZE="3"]Heilsin. Lately, I've been reaching down into the bowels of lucid dreaming, and astral projection. Every night, I've been keeping logs of my dreams, and what they could possibly mean. My latest dream uncovered a very intricate machine. It used the basic principles of...

Homework Statement I know how to do this type of problem, I'm just confused as to how to determine the distance the (4m) mass goes up . Homework Equations N/A The Attempt at a Solution So I was thinking that if mass (5m) and mass (3m) go in opposite directions then mass (4m)...

why poles of machine are always even?

We need to think of a machine problem which we are going to simulate and solve using fortran programming. Can someone please give me an idea on what machine problem to do? Something easy please coz I don't really have much idea about programming. I only know the basics. Thanks :)

Homework Statement A machine part is undergoing SHM with a frequency of of 5hz and amplitude of 1.80cm. How long does it take the part to go from x = 0 to -1.80cm? Homework Equations x = Acoswt The Attempt at a Solution X is given and convert it to metres 0.018. I need to...

Hi. I heard it's possible to use an "Alcubierre warp drive" as a time machine, if they existed. But how, precisely, would that work?

Homework Statement I have the professor's solutions for a homework we handed in. There is a part that is confusing me. We have the following equation: $$E = \frac{1}{2}(m_1 + m_2)\dot{x}^2-(m_1-m_2)gx$$ Homework Equations We want to find: $$dE/dt = 0$$ The Attempt at a Solution...

if i want to create a time machine ..., so what kind of knowledge that i should have to make the nearest possible..?

Homework Statement A horizontal cylinder on frictionless bearings has a moment of inertia of 0.8kg*m^2 and a radius of 22cm. A 15 kg mass is attached to a 8kg mass with a massless string wrapped around the cylinder. The string does not slip on the cylinder. If the 15 kg mass is released from...

Homework Statement Two masses, measuring 800g and 400g respectively, are attached to spring scales and an Atwood Machine. What will the reading of each scale be? https://www.physicsforums.com/attachments/52223 Homework Equations Fg = mg The Attempt at a Solution I think that...

Hi I'm having a very hard time trying to picture an argument in Feynmans physics volume one ). I can't picture this example he is talking about, so I wrote it down from the book and really hope someone can help me answer the question in the bottom. From the book (everything needed to know...

Homework Statement An atwood machince has a m1 = 4.92-kg block resting on a frictionless horizontal ledge. This block is attached to a string that passes over a pulley, and the other end of the string is attached to a hanging m2 = 2.46-kg block. The pulley is a uniform disk of radius...

tried to leave this on the appropriate thread but it's locked! hope your not bored of the subject ;) there are some really in depth answers and stuff to be learned. i'm (surprise surprise!) a tattooer just getting into the practicality of building machines after a bunch of very expensive...

Here is a fun philosophical question I wonder about sometimes, given that my background is in computer science and not physics. In the field of computer science, a Turing Machine is considered to be able to carry out any computation. So, philosophically, could the universe be thought of as a...

Homework Statement Given the no-load test results of a DC motor connected in shunt to be: Speed: 3000rpm Applied voltage: 239V Field current: 0.25A Calculate the motor constant K_m, where K_m = K Homework Equations not really sure about the equations to use i have these: Km = T/...

Hi, I am trying to design a Synchronous PM linear machine but do not know from where to start. The only known parameters are the required power and the maximum distance that the translator can move. Can anyone guide me on how to proceed please? Thanks Annalise

Homework Statement Consider the ideal Atwood's machine in Figure 4-65. When N washers are transferred from the left side to the right side, the right side descends 47.1cm in 0.40s. Find N.Homework Equations a = (m2-m1/m1+m2)g The Attempt at a Solution I'm honestly not sure where to start...

Any ideas about where I can hire a CNC machine designer for a personal (non-commercial) hobby project? I've emailed various people who are prominent (at least on the web) in hobby CNC designs and have received zero responses. Maybe my ideas are too wierd. My interest is in the programming...

All that's left to write in my lab report is the conclusion, and I'm failing to understand what my professor is requesting of me. In the guidelines it says, "Compare your measurements to the expected values. State and discuss whether your results are in agreement with the expected...

Someone has way too much free time on their hands. http://devour.com/video/giant-knex-ball-machine/

I'd really like for someone to explain the last bit of the equation used in the Atwood's Machine experiment. [Forget this gray part]Specifically, I don't understand what F means in F = Mg - mg = (M - m)g, and would appreciate that being defined. Secondly, I don't understand why a = F/(M+m) is...

Hello, I am looking for any exercises about State Machines, Mealy and Moore Machines, so I could study for my test. I have already googled it, but it's kind of hard to find something. Does anyone recommend a book or site, with some good exercises? Thanks in advance

Hi All, I was wondering if anyone could post some videos or some websites where I can read about Dynamics required for Mechanical Engineering i.e. related to vectors , how to add vectors , how to find the resultant. I searched YouTube but I am not really getting any good responses. I am a...

Homework Statement Please see the attached photo. (The one with the green highlighter), I haven't written it out to avoid mistakes. Homework Equations None. The Attempt at a Solution I have constructed a moore state diagram, a state transition table and come up with boolean...

In the bean machine, we usually drop the balls from the center of the top right? That's the reason why most of the balls accumulate in the middle bin. If you drop the balls from the top right corner (say) then balls should fall in the bins in the right side, right? Thanks a lot.

So I have a degree in Mechanical Engineering, access to a machine shop, and all the free scrap metal I want (steel or aluminum mostly). I also make perilously little income because I'm just a measly intern. I have a stash from my last job that is keeping me running until I can convince my...

I'm working my way through pattern recognition and machine learning using this http://www.cs.pitt.edu/~milos/courses/cs2750/ as a guide.Homework Statement We have to prove that a binomial random variable x, with a prior distribution for \mu given by a beta distribution, has a posterior mean...

Lubrication -- is fine machine oil "better"? So there is always a debate on gun forums over if lubricants marked for firearms are better then motor oil or cheaper automotive lubricants. I'm curious if anyone here has any hard information on the differences and what is better?

Hello, Imagine that we have a fluid heated up by solar energy (every day during sunlight). Due to higher temperature it would undergo thermal expansion and do some mehanical work while expanding, right? And during night it would cool down and hence compress and do some negative mechanical...

Homework Statement A system consists of a pulley and two masses m1, m2 haning from it as shown in the figure. The pulley is a disk of radius R with constant mass density that has two circular hole with radius R/2. Find the angular acceleration of the pulley. Figure attached. Homework...

Consider two stationary blocks of same mass suspended by a massless string over some kind of pulley. The net force on both of them is clearly 0. Now suppose we somehow gave on of them a downwards velocity by some kind of energy transfer. Then intuitively the block would start to fall down. But...

Our lab is looking at designing a new ECAP machine (Equal Channel Angular Pressing). It needs to be driven by an electric motor attached to a gearbox. From their modeling and data collected from their existing ECAP machine they are requesting the output shaft on the gearbox to have a 2,000,000...

Simply, what the title sugests, would going downhill on inclined plane be considered a simple machine? If so, how is this decreasing the amount of force needed?

At my work, we go through a lot of liquid CO2 (LCO2), and dealing with the 500 pound LCO2 dewars is a real pain. I'd like to look at options for us making our own LCO2 instead, but have been having trouble finding information about small-scale LCO2 generation on the web. We use the LCO2 for...

Homework Statement I currently am confused about a, probably, simple problem >.< Back in primary school and middle school, my science teachers taught me that one of the simplest examples of a wheel and axle would the the wheels of a car (in this case a toy one), which made sense to me at the...