Contact Definition and 422 Threads

Homework Statement A force of magnitude 7.50N pushes three boxes with masses m1=1.3kg, m2=3.2kg, and m3= 4.9kg as shown in the figure. I want to find the magnitude of the contact forces between boxes 1 and 2, and between boxes 2, and 3. Now, the force, 7.5N is being pushed from right to...

How to find out contact time of 2 Carrom men in carrom board game? I am trying to develop a game of carrom board. For this i want to know how to find contact time if Co-efficient of restitution and velocities before contact is known?

I know theoretically that friction is independant of contact area. However, i have a cylinder which i want to clamp via two jaws. My thinking is that a v jaw, clamping at four points around the circumference of the cylinder would be more effective than a curved jaw design?? Thoughts would be...

Hi I am having a little trouble designing a micropump out of a mini dc motor-it needs to be able to extract small amounts of liquid (approximately 50 microliters) through a small tube (diameter 0.2 cm or 2 mm) without having the liquid pass through it. Is there any way I can use the motor to...

Homework Statement A small smooth ring R, of mass 0.6 kg, is threaded on a light inextensible string. One end of the string is attached to the fixed point A and the other end is attached to a ring B, of mass 0.2 kg, which is threaded on a fixed rough horizontal wire which passes through A...

I'm trying to determine the contact surface area of a threaded bolt so that I can make some changes to the design and maintain the same contact surface so as not to affect the performace in other ways. This presents itself as a helix, and my initial guess was that it may be best to work this...

Hi, Just have a few questions about this chapter if anyone here is familiar with it... 1) Does anyone know why the k^2_i \to -m^2 limit is imposed in (67.4), is it just because he wants external particles to be physical and hence on-shell? I derived this equation from the one directly above...

considering this relay http://my.element14.com/durakool/dm84-2012-35-5024/power-relay-dpdt-2co-24vac-8a-pc/dp/1557207" what does contact DC voltage meant? and to energize / activate the coil i need a 24v current to do the job?

hi.. This is abdul I am carrying a impact of sphere on a composite laminated plate. i wanted to calculate the contact force when sphere impacts the plate.. or can anyone help me how to get the stiffness of plate.. or deflections in plate.. with respect to time Thanking you Your help will...

Hello everyone! I am struggling with calculating the normal forces for a vehicle that is in contact with the ground at three places (scoop, front wheels, rare wheels). To calculate the normal forces with two locations (such as front and rare wheel) it is just to balance the forces as well...

Hi All, I am trying to get an analytical solution to a contact problem with dynamic loading. I am not sure if an analytical solution of such a problem is possible. Here how the problem is: A cantilever beam, with its free end resting on a smooth plane, is under harmonic loading f(t)...

Hi, I am trying to do a vibration analysis of a cantilever beam in contact with Earth (in ABAQUS). Now I need to match these results with the analytiocal solution. Could any of you guide me any paper or book where this klind of a problem is solved. So basically I am looking for the...

Simulating "Bonded Contact" from ANSYS Mechanical in ANSYS APDL Hi, Im looking into the accuracy of using different element types to model a particular structure. As a simple approximation think of it as a beam split into 3 horizontal sections. Shown in the diagram as top, middle & bottom...

Do I believe there is life elsewhere in the cosmos? Absolutely. Do I think they have radio, nuclear fission, space-faring vessels and maybe even technology far beyond our comprehension? Yes, but they are likely so rare, it's inconceivable that we will ever cross paths. Why? For...

Does gravity stop accelerating objects once they are in contact with Earth's surface? If so, why?

Homework Statement After some digging, you locate your aluminum baseball bat (1.3 kg, c = 0.90 kJ/KgK) in a snowbank(0 Celsius) and bring it into a warm (25 Celsius) room. If the 64 m^3 room contains 76 kg of air (c = 1.02 kJ/KgK) and no one goes in or out of the (closed) room, what is the...

Homework Statement A uniform plank of length L leans against a vertical wall, its head a distance h above the horizontal ground. If we let go of the plank from rest, how far above the ground is the head of the plank the moment it loses contact with the wall? Homework Equations Fx=0 Fy=mgThe...

So I was talking with my physics professor a while back about how friction force in a tire is independent of how much of the tire is in contact with the road. ie: Mu*(m*g) doesn't take into consideration the size of contact area and the friction is the same because essentially the weight (m*g)...

Hello all! I'm modeling with ANSYS 12 (workbench) an assembly made up by components which are initially in "gap" condition, going in contact after deformation due to the applied pressure load. I tried in a "static structural" analysis by settings the manual contact regions type "frictionless"...

Homework Statement Two blocks are in contact on a frictionless, horizontal tabletop. An external force, F, is applied to block 1, and the two blocks are moving with a constant acceleration a = 2.45 m/s^2. Homework Equations what is the contact force between the blocks? The Attempt...

1. Problem statement I've already posted this question in the advanced calculus help but it was suggested that I ask this in the physics forum. I can upload the pdf of my work again so I'll link to it https://www.physicsforums.com/attachment.php?attachmentid=31702&d=1296270924" from my other...

1.Two homogeneous rods have the same cross section, specific heat c, and density \rho but different heat conductivities \kappa1 and \kappa2. Let kj=\kappaj/(c\rho) be their diffusion constants. They are welded together so that the temperature u and the heat flux \kappaux at the weld are...

For the equation: contact stress = {(1 / (pi[((1-v1^2)/E1)) + ((1-v2^2)/E2))) ^ 0.5} * {((Fn/b) * (Sum (1/pi)))^0.5} Where Sum (1/pi) = [(1/p1) - (1/p2)] for concave shapes in contact with convex shapes Sum (1/pi) approaches 0 as the two radii get closer, however when the two radii...

Homework Statement Before hanging new William Morris wallpaper in her bedroom, Brenda sanded the walls lightly to smooth out some irregularities on the surface. The sanding block weighs 2.0N and Brenda pushes on it with a force of 3.0N at an angle of 30.0 degrees with respect to the vertical...

Hi, I am going to contact a professor and ask him about the possibility for him to supervise me for the master degree. (Yes, we do masters first before PhD) But I have some important questions. Since this professor is from a different school of mine, I have never met or contacted him...

Homework Statement Three boxes rest side-by-side on a smooth horizontal floor. Their masses are 1.45 kg, 3.10 kg, and 5.20 kg, with the 3.10 kg one in the center. A horizontal force of 24.0 N pushes on the 1.45 kg mass which pushes against the other two masses. What is the contact force...

Homework Statement The Figure shows an approximate representation of the contact force versus time during the collision of a 42-g tennis ball with a wall. The initial velocity of the ball is 35 m/s perpendicular to the wall; it rebounds with the same speed, also perpendicular to the wall...

I see this all the time in job applications, including for the current employer section. Does it hurt your chances when you tell them not to contact them? I can understand that for former employees it'll signify that "I got fired" or "I torched bridges". I don't want my current employer to...

I came across a question in which a cubical body of mass 'm', edge 'a' is slipping down an inclination with constant velocity and torque due to normal contact force is to be found about the centre of the block. As friction will exert an anticlockwise torque= 0.5amgsinx, where 'x' is the...

Correct? Please let me know if my logic is off. =] Given Problem As shown in the figure, a force of magnitude 7.50N pushes three boxes with masses m1 = 1.30 kg m2 = 3.20 kg m3 = 4.30 kg (a) Find the magnitude of the contact force between boxes 1 and 2. (?N) (b) Find the magnitude...

I have a problem that requires me to do a simple simulation of a sheet metal stamping. I have access to Ansys Workbench v12 Academic version, and have familiarized myself with the program and tried to read up on its features and limitations. The simulation is selected as a static structural...

Before I begin, immediately after I saw my first two sightings and after reporting them to nuforc and mufon, I started refining my experience by writing thoughts down to the best degree humanly possible. Take in consideration, what I saw was not supposed to exist and I am describing how it...

I have calculated the contact stress for a sphere in a socket using formulas provided in Roark's formulas. But my problem is that the sphere is actually in contact with two sockets - upper and lower sides, so there are actually two contact areas. Can I just multiply the contact stress I...

In my attempt to obliterate my ignorance I'd like to discuss something related to the recent news story about a young man who attached two clamps to his nipples and then had a friend plug it into a wall socket. http://news.gather.com/viewArticle.action?articleId=281474978486647" <-- News Story...

I recently made my first blog post on the subject of whether http://reptoavian.blogspot.com/2010/08/alien-contact-forthcoming.html" . Do you agree or disagree with my estimates of the variables in the Drake equation? What do you think of my conclusions for the number and spacing between...

Am I correct in saying that when a torque is applied to a wheel the force is resisted by the friction at the contact patch and then becomes a "equal and opposite" torque acting around the contact patch?

Hello I just moved in with some new people who, I have found out, smoke a lot of weed. Now the internet is full of info about how passive smoking can explain a positive drug test but this is not what I'm interested in. I'm afraid I could get dumber from the passive smoke inhalation. If that's...

When I model a honeycomb type composite in workbench I tired modeling the core material as an orthogonal material type using solid tet elements and the aluminum face sheets as isotropic shell elements. I base the core material properties off of the honeycomb manufactures data for stiffness...

Homework Statement Two objects, in contact with each other, are being pushed across a table. The masses are 113g and 139g. Friction is negligible. The applied horizontal force of magnitude 0.0538N is exerted on the more massive object. Determine the acceleration of the two object system and...

I kitesurf a lot in both fresh water and salt water. I wear well-fitting contact lenses that do not shift around or come out, even if I rub my eyes. In SALT WATER: I can crater from 20 feet in the air with a thunderous crash and get dragged through and tumbled by waves with my eyes open...

Hi everyone, I need to evaluate parameters (heat capacity, density and thermal conductivity) for some very humid air. I know the parameters for both dry air and water vapor. So I suppose the parameters I need will just be a linear combination of the other parameters, with a coefficient...

Homework Statement The following camping van with a total mass of 800 kg is connected at point P to the back of a car. The car accelerates with constant acceleration a during 4 seconds from rest until it achieves 60 km/h. Assuming there is no resistance (from air and ground), calculate the...

Homework Statement Two crates, of mass 75 kg and 110 kg are in contact and at rest on a horizontal surface. A 620N force is exerted on the 75 kg crate. If the coefficient of kinetic friction is 0.15 calculate: a) the acceleration of the system b)the force that each crate exerts on the...

What does it mean for the contact between two surfaces to be "perfectly rough"?

When a metal sphere, A, with a charge of +5q is touched to a sphere,B, with a charge of -q what would each of the spheres charge would be and what would there the circle view of the final sphere? thanks

Homework Statement SO3 is not absorbed in water directly to form sulfuric acid because A. Reaction doesn't go to completion B. Reaction is slow. C. Highly exothermic. D. Insoluble Homework Equations -------------- The Attempt at a Solution MY...

I recently applied to some grad schools for a PhD program and I was notified by one particular school that while my marks were under their admission requirements, they recognize that I have valuable background experience which may allow me to succeed and that they would circulate my file to...

1. A student who's standing still on level ground weights 570 N and is wearing a backpack that is 81 N. a) What's the magnitude of net force on the student? b) What's the magnitude of the contact force on the student by the backpack? c) What's the magnitude of the contact foce on the...

Two blocks of masses m1 = 4.00 kg and m2 = 3.00 kg are placed in contact with each other on a frictionless horizontal surface. A constant force F = 9.00 N is applied to the block of mass m1. a) Determine the magnitude of the acceleration of the two-block system. b) Determine the magnitude of...

Hello all, Just thought I would throw this one out there. Who preferes to use the RBE3 command to automatically create a set of constraint equations and who prefers to use the Contact Wizard? I used to use the Contact Wizard but I recently got burned by it, so I switched to using the...