Static Definition and 1000 Threads

Hi I have seen electric technicians while racking out high tension circuit breakers, use a wire that has one end grounded and they use the other end to touch the bus bars on the breaker in case of a static charger, they carry out this procedure before they do any work on the CB in case they...

This isn't homework...I'm reviewing physics after many years of neglect. Given 2 masses, m_1, m_2, connected by a rigid, massless rod, stationary with respect to a ramp which makes an angle of \theta with the horizontal, with coefficients of static friction between the masses and the ramp =...

Homework Statement what factors affect the size of the pressure at a point in a static fluid? Homework Equations The Attempt at a Solution

Homework Statement Two solid steel shafts are coupled together using meshed gears. Determine the angle of twist of end A. Shaft DC is fixed at D. Homework Equations angle of twist = torque * shaft length / ( polar moment of inertia * shear modulus) balance of forces where the two gears...

Hi everyone, If I have a static cylinder on an inclined rough plane at an angle alpha supported by a chord under tension, which leaves the surface of the cylinder at a tangent upwards and parallel to the plane. Does the weight component trying to pull it downwards equal the sum of the friction...

Homework Statement uk of fraction between bar and both surfaces is 0.2. Bar weighs 5 kg. i) Is the bar in static equilibrium? If not, which end will fall down and which end will go up? Homework Equations F-uk*FnThe Attempt at a Solution Not sure how to even begin analyzing this. I cannot...

Homework Statement Homework Equations How to do this question ?? The Attempt at a Solution I know sum of torque and force = 0 at fapplied i got torque = 25sin(45) * 3.8m = 67.18N .. But don't know what to do next !

It is a thousand yeas ago. You, along with your friend king Ethelred the Unready, have been hunting wild boar. You've had good luck; you shot a 150 lb boar. Now the hard part; you have to carry it back to the castle several furlongs away. Fortunately you have some rope and an 8 cubit pole. You...

Homework Statement Two small balls, each of weight Wo, are supporting a big ball of weight W1, as shown in Figure Q2. The line connecting the center of the upper ball and that of a lower ball forms an angle of 45° with respect to the horizontal, as shown in Figure Q2. A block of weight Wo is...

wrong section

Homework Statement I know the diameter is 30 m and the radius is 15 The period for one revolution I suppose is some multiple of 7.03 Homework Equations The Attempt at a Solution I couldn't think of an equation where friction was involved where rotational motion was concerned. I...

Hi all, Let us say I have rubbed cat fur with nylon. Is there any relation for determining the amount of charge (in Coulombs) induced on either of the materials? Thanks in advance.

1. Homework Statement A bus passenger has her laptop sitting on the flat seat beside her as the bus, traveling at 10.0 m/s, goes around a turn with a radius of 25.0 m. What minimum coefficient of static friction is necessary to keep the laptop from sliding? Given: V = 10 m/s r = 25.0...

static balancing is when the center of gravity is in the axis of rotation. dynamic balancing is when the central principal axis of inertia is parallel and coincident with the axis of rotation. my question is, even if its theoretically, can you have dynamic balancing without static...

I'm trying to get my head around this scenario: The blocks are at rest, despite the tension forces acting on them. It is obvious that the static friction acting on A from B is 20N to the right for A to remain at rest (the max might be a lot higher). But does this produce an equal and...

Homework Statement Suppose we take a 1 m long uniform bar and support it at the 22 cm mark. Hanging a 0.29 kg mass on the short end of the beam results in the system being in balance. Find the mass of the beam. Homework Equations \tau=F*r The Attempt at a Solution I set it up so that...

Lets say you have a block on a horizontal surface connected to a pulley and then a weight hanging over the edge. If its not moving then the force applied which is just the mass of the weight x gravity is equal to the force of static friction μsmblockg. So that means μs = the mass of the...

Homework Statement A 8-kg homogeneous box X is resting against another 20-kg homogeneous box Y at an angle such that its diagonal BC is horizontal as shown in Figure Q1. The angle of static friction between box X and the floor is 45° and that between box Y and the floor is 30°. Treat the...

I keep a book that his weight is 10kg(100 Newton,lets say). My hand will feel a force of 100 Newtons. Now let's say that the book is up of a desk,and with some force(lets say 60 Newtons) I hit that. Why I will feel more pain the second time,while I feel less Newtons? It is about the time?

Can anyone explain this case ? If a moving box is pulling with a force F and the kinetic friction is 0.4F, of course, it will move in the direction of applied force with an acceleration and the net force is 0.6F But what if the force suddenly decreases to 0.3F ? The box is still moving so the...

Homework Statement A string is tied to a 4.4 kg block and 120g hanging bucket. Students add 20g washers one at a time to the bucket. The student are unaware that the coefficient of static friction for the block on the table is 0.42. A) what is the maximum force of static friction for the...

Homework Statement Two objects are made of identical material and are tied together with string. The first object has a mass of 5.0kg and the second object has a mass of 3.0kg. Students measure the maximum force of static friction as 31.4N to move both objects across a horizontal surface. a)...

1. A 1760 N force pulls a 266 lg load up a 17 degree incline. What is the coefficient of static friction between the load and the incline? 2. Coefficient of station friction = Force(Static)Max / Normal(supporting) force The Attempt at a Solution

Greetings PFers, Can someone help explain to me the difficulties of designing a device which utilizes static electric fields to map an objects’ internals and externals? My understanding is that as a electric field propagates through matter, it encounters absorption. I envision a device...

So, I don't want to disclose why I want to know about this because its to do with a friends invention and it would be unfair to publish too much information without his consent. That's my disclosure so to speak. I'm interested in how static electricity is managed in vehicles. I remember...

Homework Statement I have a box on a horizontal plane. Given data: mass = 0.25kg height of object = 14 cm width of object = 9cm Calculate the coefficient of static friction. Homework Equations μs = Ff/N (N is the normalforce) F = Ff = μ*N mg = 2.45 Newton The Attempt at a...

Homework Statement My textbook has a true or false problem that says Static Friction can never do work on an Object and they say that it's false.. How can static friction do work?

Homework Statement A 100 kg block rests as shown in Figure on a wedge of negligible weight. Knowing that the coefficient of static friction is 0.25 at all surfaces of contact, determine: (g = 9.81 m/s2) a) the angle θ (degree) for which sliding is impending and b) compute the...

Homework Statement Q) A transmission cable AB exerts a 3000N force on the pole in the direction of the tangent to the cable at A (see Fig. 1). Determine the required tension T in the wire AB if the resultant of the two forces at A is to be vertical (1 point). Find the magnitude R of the...

Hello, Is it possible for a structure to be completely constrained and statically indeterminate, or partially constrained and statically determinate? Or does one come with the other automatically? I am having difficulties determining if a structure is partially constrained or completely...

http://postimg.org/image/4ctmvwzx3/ Homework Equations Ʃτ = 0 ƩF = 0 The Attempt at a Solution summing the torques for each piece, i found Ʃτ = MgLsin(90-ψ) - mgIsin(ψ) = 0 MgLsin(90-ψ) = mgIsin(ψ) ML/mI = sin(ψ)/sin(90-ψ) = sin(ψ)/cos(-ψ) = tan(ψ) so ψ =...

I have a problem. Lets say there were two pulleys put at equal height. You have a metal ring and attach three wires to it. At the end of each wire, have three weights of mass w. One weight hangs down, one weight goes over one pulley and the other over the other pulley. The system goes to...

So with this problem, I have been thinking about it. Since it is in equilibrium, I know the sum of forces and torques will be equal to zero. However, I'm not sure how the height, h, fits into this. I know the weights have a force and are a distance away from that fulcrum, d and 2d, so I could...

Suppose a block of mass 5 kg is resting on a horizontal surface and coefficient of static friction between block and surface is 0.2. If the block is pushed against a vertical wall with a force of 200 N, will the static friction oppose the force? The body has no intention of moving as it is...

At what speed does a change in a static electric field propagate through a medium? I understand that through a vacuum it's the speed of light, but through a medium such as a conductor or insulator how fast will this change propagate? In classical electrodynamics, how do we model the...

what will happen if static pressure in supply duct is higher than the fan compartment in AHU?? or vice-versa thanks

Are there any fans of truck or tractor pulls out there? I am trying to understand what is happening to the coefficient of friction as the sled transitions from kinetic friction back to static friction. It is a fairly complicated model... The weight imposed on the front plate of the drag...

I read from the PDE book about Laplace equation in static condition ie ##\frac {\partial U}{\partial t}=0##. But is it true that even if U is time varying ie ##U=U(x,y,z,t)##, you can still have Laplace and Poisson's equation at t=k where k is some fixed value. ie...

Homework Statement Homework Equations The Attempt at a Solution i chose positive and negative but i am not sure.

Homework Statement Homework Equations The Attempt at a Solution I think it depends on induction so when the rod is brought close, the spheres will be positively charged. When they move away of it, A will get a negative charge "by induction" and B will get a positive one

Trying to get my head around something with the Darcy Weisbach. It is used to calculate the head loss of a moving fluid within a pipe. So for example if we take a pipe with an entry point 6m above a datum plane and an exit point 1m above the same datum plane. The pipe length is very long, say...

It is well known that all sorts of systems tend towards minimal potential energy. I was wondering if this applies to static electric fields also, i.e. is an electric field such that it's energy integrated over all space is minimal? For example if we have a bounded source free region and if the...

Homework Statement Show that a static, spherically symmetric Maxwell tensor has a vanishing magnetic field. Homework Equations Consider a static, spherically-symmetric metric g_{ab}. There are four Killing vector fields: a timelike \xi^{a} satisfying \xi_{[a}\nabla_{b}\xi_{c]} = 0 and...

The problem is the following, i have a rectangle as a cross section of steel, which is bended and compressed.. i want to use the equilibrium equations to make sure its static, but since the compressive force and the traction force aren't equal, the equilibrium equations make no sense here's a...

Homework Statement Consider a family of logic gates that operate under the static discipline with the following voltage thresholds: VOL = 0.5 V, VIL = 1 V, VOH = 4.5 V, and VIH = 4 V. Using the switch-resistor MOSFET model, design an inverter satisfying the static discipline for the four...

Homework Statement Mass 1 is 20Kg, find m2 and m3 and the tensions please help I do not know where to start :( Please help.

I already have this equations. But I'm confused on how to solve it, because of this 100. ΣFx=0 T₂Cos30°-T₃Cos60°-100N=0 ΣFy=0 T₂Sin30°+T₃Sin60°-9810N=0 How will I solve this? Please I Really have a problem on simplifying it, I need to solve for the T₂ and T₃

Hello folks, I'm being tricked by the pesky friction force again. I know that static friction acts just to put everything in equilibrium as long as its magnitude doesn't exceed a certain value. That is ok. But when there are other adjustable force such as TENSION and NORMAL, (which in this...

So i am confused on how to do the analysis on the pin where the hook attaches to the arm. would their be a shear and a torque at that point?

Homework Statement I´ll show the problem with a picture: Homework Equations M=rxf Sum Forces = 0 Sum Moments= 0 The Attempt at a Solution I recognize that I am completely lost with this problem, so I´ll try to analyze every force acting on every body to show where are my doubts. When...