Mechanism Definition and 511 Threads

As far as I know, ice skating works because high pressure lowers ice melting point. A thin layer of water forms between the blades and the ice which greatly reduces the friction. Just now, I am reading a thermodynamic book. For the phase boundary between ice and water, dP/dT ~ 135bar/K...

I thought Hawking radiation was a virtual particle pair emerging from nothing, one particle falling into the event horizon and the other particle tunneling out of the event horizon. Then I read this - https://www.physicsforums.com/insights/vacuum-fluctuation-myth/ and now I think a virtual...

Homework Statement Homework EquationsThe Attempt at a Solution Can't find this exact reaction mechanism online. Help? http://imgur.com/a/X9P7e I don't know what the mild oxidation does. Does it split the double bond into a ketone and aldehyde?

Homework Statement [/B] Begin with a solid cylinder of mass M and radius R. A hole is bored through this cylinder with radius r < R/2, parallel to the axis of the cylinder and with the surface of the hole touching the cylinder’s axis. This modified cylinder then rolls on a horizontal surface...

How would you write the vector loops and geometric constraints for this mechanism?

How does the Gall Wasp get an Oak tree to make these? http://ento.psu.edu/extension/factsheets/galls-oak https://en.wikipedia.org/wiki/Gall_wasp I am not able to find anything other than "induced by chemicals secreted by the wasp" more or less. I have been looking at these over the last six...

Having trouble researching/discovering any locking mechanisms that engage with force in a linear direction and then allow the engagement to be released with force in the same applied direction. I don't know if it has been done, any help/findings would be greatly appreciated. The only technology...

Friends! I have some things unclear about diamagnetism in matter.Please see attached picture.

First let me ask this: Consider a pair of entangled photons fired at a respective detector after passing respective polarisation filters. If a photon passes a polarisation filter, is it in a superposition of having passed and not having passed? Is the measuring device (that detects the...

I've been doing some reading about SPDC. I understand the wave mixing, the conservation laws, the coupled equations for the three fields (pump, signal and idle). But I can't find any good reference on how does the split happens? (how the two photons are created) Is it because photons of the...

Hey guys :) So I'm looking to form equations that I can apply a Laplace transformation to. The mechanism specifically is a trailer jack - it converts rotational motion to linear motion. And its high torque provides a mechanical advantage to lifting heaving loads. Can anyone help me form...

Hello everyone, I am currently doing an internship and I am working on a part that opens and closes using a pneumatic cylinder as you can see bellow Here is a force diagram I would like to redesign this in order to use a cylinder with a shorter stroke and perhaps a slightly bigger diameter...

I have a mechanism that controls the movements of multiple assemblies in the X Y and Z directions. The mechanism has been built and suffers from a wobble on a fast X travel. We have a few suggested solutions but it would obviously be a good idea to get some calculation to help prove a solution...

i need I need to design this mechanism, but have not found the design criteria or how, someone could show me how or where to look. I need to design the mechanism that puts the lid to the product. but not with pneumatic actuators. in the following videos you can see how it works:

Hi, I'm trying to design a contraption for a project that will move an item/box up and to the side. I have a picture of what it should look like and how it should look like but I need help with the mechanics of it. The box's starting position is In the ground and under a slap of metal or wood...

Firstly, am struggling to wrap my head around exactly how the mechanism for a traditional 'hills hoist' (as seen below) clothesline functions. The handle can be turned in order to raise the clotheslines but from my googling, the mechanism is different to what I was expecting. Would be...

Hello All. I'm searching for this part and also have video footage of it in motion. I cannot find it to finish the eye mechanism because I don't know what it's called. Can anyone tell me what it is? I would greatly appreciate it. Even companies dealing in such parts as well as metal...

Hi, I am trying to build (or at least conceptually) design a diy autonomous lawnmower. I want to add an automated grass cutting height mechanism. I have never worked with lawnmowers but through basic googling know that most lawnmowers have simple mechanisms in wheels to change cutting height...

https://scontent-lhr3-1.xx.fbcdn.net/v/t34.0-12/13181084_10156883800920486_1357045350_n.jpg?oh=a39d7777f01c4aa06301c4f3d740de1e&oe=57301DBC Hi I am currently studying design engineering and my lecturer has left just before an exam. I really don't know how to find the magnitude and direction of...

I want to design a crank mechanism. I found this page on Wikipedia https://en.wikipedia.org/wiki/Piston_motion_equations Relating from this diagram, is x the max stroke of the piston ?, or is it PO-(max stroke of piston) ? And why is l^2 = r^2 + x^2 - 2*r*x*cos(A) Shouldn't it be, l^2 =...

How much force required to pull the actuator pin from the solid cylinder Weight of the solid cylinder is 15kg And angle of inclination 30 , Coefficient of friction 1.5

This is a hard one to describe and I couldn't think of a better tittle, sorry. My aim has been for a while to create a mechanism which allows me to move an object (i.e a washer or something) in or out radially along a spoke of a wheel. However I have some restrictions which have made me scrap...

Homework Statement What is the product of 1-bromo-3-propanone treated with vinyl lithium? Homework EquationsThe Attempt at a Solution I know that the carbonyl is attcked by the organolithium but I am having a hard time understanding how it attaches to the carbonyl since it is sp2 hybridized...

Let's say you have a monochromatic laser beam directed towards a light sensor. As you move the sensor away from the laser, the intensity read by the sensor will decrease because of scattering on air molecules (extinction). Since intensity is proportional to the square of the E-field amplitude of...

Hello, I want to design a mechanism for tilting an air hose (not more than 10 kg) to a desired angle (anywhere between 0 and 90 degrees depending on operating conditions) and holding it there. I've tried googling this up but just can;t find what I was lookin for. Then I searched for...

I need to find the mobility of the pictured system I have labeled the 5 links with black numbers and the 6 joints with red letters for convenienceAttempt at a solution: I know the mobility equation is M = 3(N-1) – 2(J1) – J2 + R, where N = number of links, J1 is the number of 1 DoF Joints, J2...

Hi all, I am working on a slider crank mechanism for moving an object of about 100 kg back and forth 30 mm at about 600 rpm. I plan to attach the connecting rod onto a flywheel that act as a crank, or attach to a pulley (in case need to use a transmission system to reduce input speed, increase...

Put simply, is the explanation for velocity-based time dilation toward the end of this video correct? http://www.iflscience.com/physics/teenager-wins-400000-his-video-explaining-einsteins-theory-relativity Considering he won $400k in an international science video competition, you would hope...

Hello, first of all, I understand, how microwave tube works but I'm interesting in how exactly the microwave heat up a things? What's the matter inside. I have heard about increasing energy of molecules of water by polarization them by micro-wave. But I have got a plate which is not from...

Before starting I want to say that this topic is from a subject I'm taking called vector mechanics. The subtopic dealt is called kinematics of rigid bodies. Homework Statement The wheel rotates around an axis. This point of reference of the center of the wheel is labeled as "A". This wheel...

Can anyone give a detailed mechanism for the tautomerization in AgCN and AgNC and is the same possible in KCN and KNC ??

Hi everybody, At wiki, I was astonished to read this about diffraction of light : "In Quantum Mechanics, it is a remarkable fact that the mechanism of diffraction is based on radiating particles of a medium, while quantum mechanical waves have no transmitting medium. As being part of the...

Information : CS11G Manual operation or CJ6B motor operated , for GW4F-145 type dis-connectors, Hi Friends, i am very confused, about dis connectors , if these are Off Line operated then what is the use of Motor operated ? 2nd , if motor operated mechanism is installed then controls of that...

I asked this question to PhysicsStackExchange too but to no avail so far. I'm trying to understand the way that the Higgs Mechanism is applied in the context of a U(1) symmetry breaking scenario, meaning that I have a Higgs complex field \phi=e^{i\xi}\frac{\left(\rho+v\right)}{\sqrt{2}} and...

I built just a long pendulum in my house in order to start looking at a simple Foucault pendulum "prove the Earth moves" event at the science museum I'm helping to start here in Pensacola. It gave me a nicely reliable movement that seemed to show the pattern I was looking for. Every time, it...

Hi. I am working on a project that requires moving a small camera on a platform in a linear fashion. I have a rectangular board and this camera need to move from one end to the other controlled by an arduino or something similar. I don't even know how to begin to approach this problem. I am...

What would be the appropriate mechanism such that when the eccentric circle is rotating about the larger center circle the table stays horizontal? The large circular is the driver (its continuously rotating)

Homework Statement Calculate the DoF (mobility) of the following system: Homework Equations [/B] M = 3(L-1) - 2J1 - J2 (where L = number of links, J1 is the number of full binary joints and J2 is the number of half joints. The Attempt at a Solution I am very confident about there being...

As I know, when a link in a kinematic chain is fixed, the kinematic chain will become a mechanism. And, I only know the definition of the DOF of a mechanism. Is there the definition of the DOF of a kinematic chain ?

Hello all, I need help identifying the following pivoting joint, and also coming to an understanding of how this particular joint works and is designed... Thanks for your help!

So I was sitting around pondering about forces, and I found myself thinking about shock-waves. Whether they're caused by supersonic travel, or explosions, the pressure at the front of the wave-bow shock pressure is a force. So I started thinking of a way to generate them without having to go...

Hi all, I was wondering if anyone had any ideas on something I'm struggling with at the moment. In the attached picture I have a sliding plate that needs to travel as shown. I have a motor mounted in the position on the picture and due to limited space its the only position available. I had...

Homework Statement A) Determine the value of the angle θ (measured from vertical) when the angular velocity of link AB a maximum. B) What is the maximum angular velocity of link AB. Homework EquationsThe Attempt at a Solution This is a part of a bigger question. I've managed to answer all...

Hey guys!, this is my final year aeronautical engineering project that me and my group are going to work on! we have this concept of producing a roll in an uav/RC aircraft by reducing the area of the wing on one side while keeping the other side area constant or increasing it(gradually) and...

From what I have read, it sounds like GR predicts that under certain conditions, space itself will expand. If this is incorrect, please just let me know and ignore the below. While I don’t know the math involved in GR, I can understand explanations of how gravity distorts space-time, to alter...

Hello, I ran a search online and found some examples of Nichrome and Ring and Hook based mechanisms, but i don't have enough experience to make an intelligent decision for my project. Does anyone have a good source of information for these things? Thanks.

Hi all, I'm new here on Physics Forums and can't wait to delve into some juicy topics! I have a very practical problem that I need help with. I am doing a home project where I want to move a platform on wheels (loaded to a maximum of 70kg) in a 1.5m long straight line across the floor at a...

Hi everyone, I am making a hexapod ( six legged walking mechanism ) which walking by keeping 3 alternate legs in air and other 3 on ground, pushing the body ahead, also known as tripod gait. The basic structure of model and one leg are shown in the pictures. I want to calculate the torque...

I have looked in a lot of different websites for a explanation of the mechanism of the ebolavirus to infect our body: how it avoid our immunology system, what it exactly change from our DNA and the consequences in the body. I didn't found a clear information, can someone help me to understand ebola?

I have a geared DC motor taken from a hand drill. When I manually turn the internal motor, the drill bit rotates. This can be done in both directions. However If I try and turn the drill bit it does not rotate. What is the mechanism called that achieves this? My friend says it is a sprag...