Static Definition and 1000 Threads

Is it possible to use an electrical current (from mains electricity) to create static electricity on a conductive surface (that is not earthed) without the two coming into direct contact? See attached image.

Hi friends Problem is - https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-ash3/s480x480/548739_2677144185130_1329975308_n.jpg Attempt - Well the potential at the origin is 10V. But if we move a distance of 1unit from the origin in any axis, the potential becomes 8 V. The difference is...

Question that's been boggling my mind all day lol.. If the Earth was completely static (Not spinning around its poles, the sun, the galactic center, or moving away from the center of the universe) would time still be measurable?

I have studied a few online sources about static equilibrium in a mechanical system. My overall understanding is that for an object to be in static equilibrium, two following conditions have to be fulfilled: 1) Vector sum of all external forces that act on body must be zero. 2) Vector sum of...

Hello, I am currently reading the about the topic mentioned in the title of this thread. In my textbook, the author gives the example with the wine-bottle and it's holder (I attached a photo). In this example, the author states that in order for this to be in static equilibrium, the second...

Homework Statement I am trying to derive the line element for this geometry. But I am not sure how to show that ds can't contain any crossterms of d\theta and d\phi Homework Equations ds must be invariant under reflections \theta \rightarrow \theta'=\pi - \theta and \phi...

Homework Statement So a hot wheel was put on a linear track, and one end of the track is slowly lifted until the cart starts to move. The height of the one end is measured as 6.45cm and distance (or hypotenuse) is 189.5cm mass of hot wheel is 45.7 g Homework Equations PE = mgh KE =...

Suppose a square metal mesh sheet is hung off-center from a string and you are charged with the task of hanging various weights so that the mesh will be in static equilibrium, roughly horizontal. Why is it that this task must be done with masses that can exert torques large enough to flex the...

Homework Statement We have a car with mass of 1200kg driving at 55km/h. It suddenly starts breaking. The breaks "work" on every of the 4 wheels with the constant torque of 12Nm. The radius of the wheels is 0,21m. Question 1: How long does the car travel before it stops if the wheels have...

Like the question says: if a particle is perfectly static with respect to the Higgs field, can we still define mass or is mass then irrelevant? On another note, (and if I am not mistaken) why does mass not vary with a particle's speed with respect to the Higgs field? IH

Hi there, the full question is as follows: Suppose omega_m = 0.2. If we observe cosmic acceleration at z=0, what is the possible range of values of q_0? What is the minimum value of lambda? What is omega_total? so I'm having trouble with the relationship between q_{0}, \Omega_{m,0}, \lambda...

Hi, I appreciate the basics if static models, but I'm wondering just how static they are. I understand there is no expansion, but is there any element of evolution? (For example, colliding galaxies, collapsing dust clouds, etc.) Regards, Noel.

Homework Statement In Figure, a 103 kg uniform log hangs by two steel wires, A and B, both of radiuses 1.20 mm. Initially, wire A was 2.50 m long and 2.00 mm shorter than wire B. The log is now horizontal. What are the magnitudes of the forces on it from Wire A, and Wire B? Ysteel= 2.00*10^(11)...

Layden jar questions? :) And some static electricity questions.?? Hello. I'm making a layden jar and i am kinda changing some details in it. and i want to ask if those will affect anything in the performance and if it's shocks can be lethal.. http://postimage.org/image/s9xqthylt/...

Homework Statement A painter (mass 61 kg) is walking along a trestle, consisting of a uniform plank (mass 20.0 kg, length 6.00 m) balanced on two sawhorses. Each sawhorse is placed 1.40 m from an end of the plank. A paint bucket (mass 4.0 kg, diameter 28 cm) is placed as close as possible to...

Hi. me and my friend have a problem that we can't really agree upon. we are doing an analysis study on a bike's crank and pedal. the first picture shows how we put the force of 210 N. picture 2 shows how we used "fixed geometry" to lock the part in place. now, this is the static...

Homework Statement I am trying to start a project. My first step is to figure out the time a car fell off of a cliff. I know the height of the cliff which 40 meters, the base of the cliff from the car when it reaches the bottom which is 30 meters. The car has a static friction coeffiecient of...

Hi all, I'm in an algebra based physics class so I apologize if the way I approach the problem is different from what you might be used to. A buddy of mine is calc based physics always gets confused about how I set the problems up. Also, this is my first post! Thanks in advance for the help...

You need to move a 235 kg refrigerator away from the wall to clean behind it. The sliding μ is .375 and the static μ is .535. You can apply a force of 1250 N. a) How much force will it take to move the refrigerator. b) Once it is moving, how fast can you accelerate it. Can someone please...

Folks, Can anyone point me to an online source detailing an example of the static condensation process in finite elements. I believe sub structuring is another term used to describe the same process. Regards Bugatti

A flatbed truck and Static Friction and Crate "breaking loose" Homework Statement A flatbed truck is going downhill on a slope of 10 degrees at a constant speed of 20 m/s (a little over 50mph). A crate of 500 kg is sitting on the flatbed , without being attached by ropes or cables. The...

Kinetic and Static Friction Problems Please Help! Mr. Bob slid a 250g plate 1.35m across the dish return counter. It slowed with a constant acceleration for 0.85s before coming to a stop. a) Find the magnitude of the force of friction b) What is the coefficient of kinetic friction...

Homework Statement In order to hold a book of mass m stationary against a wall, you must push horizontally with a force of at least P. a. make a force diagram and find the coefficient of static friction b. calculate the coefficient of static friction for the wall and book when at least a...

Homework Statement A small crane is lifting a 10kg box of nails. If the coefficient of static friction is .4, calculate the angle at which the box begins to slide. Homework Equations Fg x component: mg sin Ff = ukmgcos The Attempt at a Solution Fnet = Fgx - Ff Would the net force...

1. Homework Statement [/b] A box weighing 100N is at rest on a horizontal surface. The coefficient of static friction between the box and the surface is 0.5, and the coefficient of kinetic friction is 0.25. If the crate is pushed with a force of 20N parallel to the floor, which of the following...

Homework Statement I know that static friction is normally almost always more than kinetic friction. But I do not know how to prove that. I have to find formulas to find static and kinetic friction, but when the object is at rest or constant velocity, F-µ(Fn)=0. It is the same equation for...

Homework Statement The problem is While trying to decide where to hang a framed picture, you press it against the wall to keep it from falling. The picture weighs 5.0 N and you press against the frame with a force of 6.0 N at an angle of 40ºfrom the vertical. What is the coefficient...

Hello, I am looking for research results, report etc. dealing with -aerodynamic efficiency and static longitudinal stability- Couldn´t find anything useful yet! Any ideas would be very much appreciated. Best Regards, granby

Hi all, I have this mechanism and I have to calcutate the spring applied by the spring to stand the force F. I have done a simple analysis but unfortunately it's wrong since I get the system is never in equilibrium. http://imageshack.us/photo/my-images/651/scissor2.jpg/ Would...

Homework Statement A very strong 100kg man is having a tug of war with a 1500 kg elephant. The coefficient of static friction for both on the ground is 1.0. a) Find the force needed to move the elephant. b) What would happen if the man could actually exert such a force? Homework Equations Ff =...

How do you use the angle of uniform slip to calculate the coefficient of static friction? Is there an equation for this? I cannot find it in the module on friction provided with the course... thanks! I found somewhere that tanθ=μk, but that doesn't really help me, as i am looking for μs...

Homework Statement A father gives his daughter a ride on a sled by applying a force F at an angle θ = 26.0° with respect to the horizontal. If the coefficient of static friction is µs = 0.153, and the combined mass of sled and child is m = 24.0 kg What is the minimum amount of force...

Homework Statement A crate, mass = 275 kg, sits at rest on a surface that is inclined at 20.0° above the horizontal. A horizontal force (parallel to the ground), F = 583 N is required to just start the crate moving down the incline. 2. The attempt at a solution U = (((mg sin (∅)) +...

Homework Statement A crate, M = 277 kg, sits at rest on a surface that is inclined at 20.0° above the horizontal. A horizontal force (parallel to the ground), F1 = 594 N is required to just start the crate moving down the incline. To the nearest thousandth, what is the coefficient of static...

Homework Statement A crate of weight Fg is pushed by a force P on a horizontal floor. (a) If the coefficient of static friction is μ s and P is directed at angle θ below the horizontal, show that the minimum value of P that will move the crate is given by P = usFgSecθ / (1 - usTanθ)...

Ok so I already know how to solve it by looking at an example my teacher did in class... This is what I did... 4. A 2.00 kg block is held in equilibrium on an incline of angle θ = 70° by a horizontal force vector F applied in the direction shown in the figure below. If the coefficient of static...

If I rotate an object about an arbitrary axis, I can draw an arrow along that axis, and assign it a length proportional to the amount of rotation. I can project that arrow onto the basis of a rectangular coordinate system. The question arises, is it a vector? I can certainly transform it...

The Known: Mass=2000kg Velocity=50m/s Radius=1000m With the given information the lab worksheet I'm working on is asking me to deduce the coefficient of friction so that I can manipulate the data and answer some questions. The problem I have is that I am not entirely sure that this could...

Homework Statement A 1980kg car starts from rest at point A on a 5° incline and coasts through a distance of 158m to point B. The brakes are then applied, causing the car to come to a stop at point C, 21m from point B. Knowing that slipping is impending during the braking period and neglecting...

Given a circle with a point mass attached, what is the relationship between the linear force and the force of static friction as it rolls without slipping? Each force diagram I made (http://imgur.com/a/xK8i1) seems a plausible place to start: a makes no torque, b makes no linear force, c makes...

Homework Statement A crate is being pushed up a hill with friction. Given: m1 = 131 kg, θ = 23°, \mus = 0.15, and \muk = 0.08. If the crate isn't being pushed anymore, what will be the magnitude of the acceleration of the crate sliding downhill? What force must be exerted to move the crate...

Homework Statement Below are six crates at rest on level surfaces. The crates have different masses and the frictional coefficients [given as (μs, μk) ] between the crates and the surfaces differ. The same external force is applied to each crate, but none of the crates move. Rank the crates on...

Homework Statement A horizontal stick of mass m has its left end attached to a pivot on a plane inclined at an angle theta, while its right end rest on top of a cylinder also of mass m which in turn rests on the plane as shown. The coefficients of friction at both points is (mu). Sorry I...

1. The homogeneous square body is positioned as shown. If the coefficient of static friction at B is 0.40, determine the critical value of the angle theta below which slipping will occur. Neglect friction at A. The image: 2. NA is the Normal force at A, which is perpindicular to the...

Homework Statement A crane is raising a plank carrying two boxes that only differ in weight. The boxes weigh 10kg and 20kg respectively. As the plank tilts toward the heavier box, predict which box will start to slide first. Explain your prediction. Homework Equations Coefficient of...

Hey all, I was going through a few video lectures on youtube. To be specific, this is the video I watched. Now, the professor in the video talks about Dynamic reduction techniques and puts Guyan reduction in that category. For a fact, Guyan reduction is also called Static condensation and...

Homework Statement we know that, every force systems can be generally replaced by a resultant force(R) and a couple(M) at a point O and the position of point O is optional. but magnitude and direction of M is dependent to this point while magnitude and direction of R is independent. In static...

Hi all, I had a thought earlier about magnetic forces. If there's a magnet attached (at rest) to my fridge, then there is a magnetic force on the magnet towards the fridge and vice-versa. This force stops the magnet from falling because of the frictional force between the magnet and the...

1.we know that generally, every force systems can be replaced by a resultant force(R) and a couple(M) at a point O. the position of point O is optional. but magnitude and direction of M is dependent to this point while magnitude and direction of R is independent. In static equilibrium R and M...

Homework Statement A child pulls a string attached to a block of mass m = 1.5 kg at an angle θ = 35.5° with an increasing amount of force. When she pulls with a force F = 7.39 N the block just begins to move. What is the coefficient of static friction between the block and floor...