Static Definition and 1000 Threads

I want to create lift of an object about the size of 36 in by 8 in. the lift would be provided by compressed air and the object would have an air dam and skirt (like hovercraft) and lift approx 250 lb mass on it to floatation level of .05 in (where skirt would not reach above lift surface...

Homework Statement A door, essentially a uniform rectangle of height 2.00 m, width 0.87 m, and weight 130.0 N, is supported at one edge by two hinges, one 35.1 cm above the bottom of the door and one 164.9 cm above the bottom of the door. Calculate the horizontal components of the forces on...

pHomework Statement A 5.03 box sits at rest at the bottom of a ramp that is 8.76 long and that is inclined at 30.0 above the horizontal. The coefficient of kinetic friction is 0.40, and the coefficient of static friction is 0.50. What constant force , applied parallel to the surface of the...

Homework Statement Two blocks of equal mass are connected by a rope of negligible mass that is passed over a frictionless pulley as shown in the figure. The angle made by the horizontal plance and the ramp is 30 degrees. a) If the system is in this configuration and neither block moves what...

I have this situation: I know that tension and friction act poining at left. Weight is obviously downward but then I need a force pointing at right for the rod to be static, and the only force left is the normal force but why should it be pointing at left? Isn't it vertical? Thanks!

Poynting vector is flow of energy per unit area. Dose it apply for both static field where E and B are decoupled, AND time varying EM field where E and B are coupled?

Hi all, hope i can get some opinions here on a topic discussed at work. Flow is exiting a pipe from a chamber at P_in to outside/atmospheric with pressure patm, at say low mach number 0.05. At the exact exit plane of the pipe, is the total pressure equal to the patm, or will it instead be...

The (0,0) and (r,r) components are: g_{00}= -e^{2\phi},g_{rr}=e^{2\Lambda}. From the first component, combined with the fact that the dot product of the four velocity vector with itself is -1, one can find in the MCRF, U^0=e^{-\phi}. What does this mean? In the MCRF, the rate of the two clocks...

Hello, I have a [probably silly] question regarding particle pair production in strong static fields. Take for instance the finite Coulomb field (of say an extended nucleus) and the Dirac equation. One can compute the bound states of such a system and see that at a certain value of Z the...

Homework Statement I just need to know how to access an arraylist that was created in a class (call it Company). In class CompanyTest, I need to access a list of employees that was created in Company. This is Company class: public ArrayList<Employee> list = new ArrayList<Employee>()...

Homework Statement It's a cilinder of mass M and radius R rolling without slipping and I'm asked to find the maximum value of the static friction coefficient for the cilinder to roll without slipping. Homework Equations Non-slip conditions: \displaystyle v=\omega R \displaystyle...

Homework Statement The attached figure shows a weightless bar with several forces applied to it (all in New). The distances are as follow: AB=6m, BC=1m and CD=3m. The question is to calculate DE so there is equilibrium. Homework Equations ƩM=0 (Rotational equilibrium)...

Homework Statement Homework Equations See my work.The Attempt at a Solution

A block is sliding down a 30° incline at 1.2ms^-2 Find the coefficient of static friction. [g=9.8ms^2] I am stumped.. Some relevant equations: Fr = μ(Fn) Fn = mg Ultimately I got μ=0.5 ---> This was through mashing and playing with some trig.

Homework Statement A door made of a uniform piece of wood measures 1 m by 2 m and has a mass of 18kg. The door is entirely supported by two hinges, one at the bottom corner and one at the top corner. Find the force (magnitude and direction) that the door exerts on each hinge. Assume that...

Can two massive particles have parallel spacetime trajectories? It seems that the answer is - no. And the closer they are the more they can't. But in that case we can't have static structure consisting of massive particles. Any composite structure would have to have something like phasespace...

I'm trying to understand why static discharge (or just plain high voltage) damages semiconductors, in particular integrated circuits. What happens when a chip gets hit by a voltage spike that it can't handle?

Homework Statement Suppose we have a two blocks of masses m1 and m2, one on the top of another. The lower block is attached to a spring which is attached to the wall. These two blocks are on a zero-friction floor. We give the lower block a velocity so that the upper block is not sliding on the...

Can anyone explain this to me? If we have an infinite amount of balls arranged in a kind of cubic matrix, in an infinite and static space...how the heck would that collapse on itself due to gravity? Thanks folks

Hey all, First off, I'd like to mention that I am completely unfamiliar with this ANSYS and have been fighting with this program for last 2 and half weeks. Any feedback and help is greatly appreciated! Please refer to the photos attached for referral. My project currently involves analyzing...

Homework Statement Very simple problem; I have three classes, Company, CompanyTest, and Employee. CompanyTest gets a bunch of information together about an employee, like salary, address, etc., and then it creates an Employee object using the Employee class. Great, so I have successfully...

The standard layman description of QED is that forces are no longer mediated by fields present at all points in space, but by particles that are (presumably?) at least somewhat localized, and carry some energy. Forces are then exchanged between two electrons by "exchanging photons" -- at the...

Hi First off I'm not a student, this is purely a curiosity question In pascals law classic drawing if you added a piston inside one of the cylinders what would happen? I've added a drawing to clarify I'm totally split on what the answer is, Pascals law seems to state the pressure on...

I have a Mathematics C assignment, with one question being about static and dynamic friction. But I think it fits this forum. Anyway, we need to conduct experiments to show if there is a difference between static and dynamic friction or not with three different surfaces. The weight of the...

I have a Mathematics C assignment, with one question being about static and dynamic friction. But I think it fits this forum. Anyway, we need to conduct experiments to show if there is a difference between static and dynamic friction or not with three different surfaces.The weight of the object...

Hi everybody! Please explain to me how can we consider static electromagnetic field in point of view of Quantum Field Theory.Because varying electromagnetic field can quantize to photons,so we can consider varying electromagnetic field like a ''set'' of photons. Thanks very much in advance.

What does static mean ? Why is a positive charge attracted to a negative charge ? What makes them attractive ?

I was just wondering how static electricity has a high voltage. Is it because of the difference of charge between the two objects e.g you and the ground? Or is it due to the electric field which surrounds an static charged object, so the electric field cause ions to build in the air allowing...

Homework Statement A 1380 N uniform boom of length ℓ is supported by a cable, as shown. The boom is pivoted at the bottom, the cable is attached a distance 3/4ℓ from the pivot, and a 3604N weight hangs from the boom’s top. Find the tension of the cable. here is a picture of the diagram...

Homework Statement a bus passanger has her laptop sitting on the seat next to her while the bus moves at 10m/s, the bus goes around a turn with a radius of 25m. what is the coefficient of static friction in order to keep the laptop from sliding? Homework Equations The Attempt at...

I'm looking over my notes here, we have a rolling disk down an incline plane and my goal is to find its acceleration in terms of its moment of inertia My dilemma is, when finding the torque, I look at all 3 of the forces influencing it (normal, gravity, and the f_s). The n goes through the...

I do not understand how to solve static equilibrium questions. Like those: Or this one http://www.chegg.com/homework-help/questions-and-answers/a-uniform-120-lb-beam-is-supported-in-a-horizontal-positionby-a-pin-and-cable-as-shown-in--q701621 The second one with the pin is especially hard...

In quantum field theory do we "describe" static electric fields with proper combinations of transvers propagating photons? Is that a basis? Is there a basis using the longitudinal and timelike photons to describe static fields? Thanks for any help!

Is paint a conductor of electricity? Since we charge the paint and let it move to the metal body of a grounded car so an opposite charge on the car. So when the paint reaches the car will the paint get discharged or will the charges on the car remain the same? Like the paint and the car body...

Homework Statement a 1450 kg car is towing a trailer of mass 454 kg. The force of air resistance is 7471N[backward]. If the acceleration of both vehicles is 0.225m/s^2[forward], what is the force of static friction on the wheels from the ground? Homework Equations I am able to find Force...

Homework Statement A plank having length L and mass M rests in equilibrium on two supports (1 and 2) that are separated by a distance D. The supports are located at equal distances from the enter of the plank. A mass m hangs from the right end of the plank. If L=6m and D=2m, which of the...

Suppose a closed loop with constant current around the loop. The loop is in a uniform constant B field. The force is \vec F=I\left (\oint_c d\vec l\right ) \times \vec B. Being a closed loop \oint_c d\vec l=0. So there is no force acting on the loop. BUT at the same time, we know there...

Homework Statement A car is going down an incline with a constant acceleration. [b]How much work was done on the car by the force of the road going down the hill? (neglect energy losses due to air resistance, rolling friction, etc.) The Attempt at a Solution There are 2 forces acting on...

Can static pressure be induced to becoming dynamic pressure through the use of "right-angle forces" with respect to particle velocities? I imagine that one could accomplish this with an ionized gas and a magnetic field. This would reduce the amount of work that is need to accelerate the gas...

Homework Statement Suppose you have two isolated conducting spheres that are both neutral. You move 2mC of charge from one to the other. a. What is the charge now on each sphere? My solution: One sphere is positively charged with 2mC more protons, while the other is negatively charged with...

Hypothetically, if I had a sphere and a block (of the same mass and material (hence the same coefficients of static friction for both interfaces) both stationary on a surface, they would require the same force to initiate motion? Once moving, a coefficient of sliding friction is employed in...

Homework Statement A uniform beam of length L and mass m shown in the figure below is inclined at an angle of θ to the horizontal. Its upper end is connected to a wall by a rope, and its lower end rests on a rough horizontal surface. The coefficient of static friction between the beam and...

I am trying to understand the derivation of a solution of Einstein's field equations for a static, spherically symmetric spacetime (chapter 10 of Schutz's 'A first course in general relativity'). The derivation defines a static spacetime as one satisfying two conditions, one of which is that...

For hollow sphere rolling up incline: I know that the kinetic friction will equal 2/3 acceleration since: μgcosθ=2/3a acceleration = 3/5gsinθ so...kinetic friction = 2/5gsinθ But how I do calculate the force of static friction??

I searched the last few months of static topics to get a basic understanding how how it happens, but I don't know how to solve my problem. I have a new couch that causes me to shock metal things I touch after standing up. I also have a computer floormat that seems to cause the same thing...

Homework Statement The figure shows a model of a crane that may be mounted on a truck. A rigid uniform horizontal bar of mass = 90.00 kg and length = 5.200 m is supported by two vertical massless strings. String A is attached at a distance = 1.600 m from the left end of the bar and is...

This isn't part of a homework question or anything, i was just curious If an object is at rest, static friction is at work, so for an object to move, on a flat surface, force applied must be greater than the static friction force yes? But this is not true for kinetic friction, where an...

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 If a body is acted upon by clockwise moments of 75 N at 1.25 m And anticlockwise moments of 50 N at 1.3 m , Is it in a state of static equilibrium ? If not what is required to achieve a state of static equilibrium ? Homework Equations sum of all forces on all...

Hello all, I am an engineering student currently undertaking a project at univeristy. It involves the sorting of 4 different balls of which I have deduced how to sort 2 of them leaving just 2 types of balls to sort... The remaining two are of identical size, 10mm in radius, and are...