Static Definition and 1000 Threads

Okay, I have been reading when we walk, it is the static friction that propels us forward. See below: "When we start running we exert a force on the ground. That's why ground also gives us a reaction force equal and opposite to the force exerted by us. The horizontal component of that reaction...

Are there any instances where kinetic coefficient of friction greater than static coefficient of friction? Is this possible in nature?

Could you please explain the term 'co-efficient of static friction'? why do the banking of roads or tracks depend of co-efficient of static friction?and not on the co-efficient of kinetic friction?

Let's say you are rubbing a balloon on your hair to make it charged. If you then discharge the balloon and rub it on your hair again (and repeat this process numerous times). Would your hair run out of electrons so eventually you would be unable to charge the balloon, or would your hair gain...

Below is a sketch of a truss in which external support reactions are given as R1 = 0 kN, R2 = 3.5 kN, R3 = 4.5 kN. Members (M) are labeled in boxes, joints labeled in circles, and forces R. Draw 2 Free body diagrams, one for each joints C and E. Define what direction represents a positive...

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I am trying to analyze if the bolts in my design are sufficient to support the load on a shaft. Unfortunately, the bolts are not all located on one face, and though I know how to analyze each face by itself, but I would like to be able to combine them all into one problem. I have attached a...

Summary: Does a static magnetic field affect a weaker pulsed magnetic field close by? If you have a static magnet close to a low level pulsed electromagnetic field, will the static magnetic field influence the pulsed field if the static magnetic field is the same strength or stronger than the...

If I can determine the weight of that heavy object placed on the plank, I will be able to determine the stretch of that wire. But, when using the second condition for static equilibrium (torques of the system equal to 0), I always end up with two unknowns, no matter what point of rotation I...

I have a solution, However Cant understand 1 point.Now, This is the solution: ##N_2 l cos\theta + \frac 1 2 F_g l cos\theta - f_2 l sin\theta = 0## ## N_2(1 - \mu tan\theta) + \frac 1 2 F_g = 0## This is the the point that I don't like - yes it is less that 0, but it's even less that...

If you see the $\sum \tau_0 = L\cdot N_1 \cdot cos \theta - LF_1 sin \theta - L/2 \cdot G cos \theta$, all the trigonemetric parts are all opposite of what i can understand, given the angle as drawed in the Picture/url. Please help me :)https://pasteboard.co/IiXr8qA.png

The bracket shown in figure 1 is applied to both ends of a beam (figure 2) which experiences a single static load at its center. The bottom of both brackets are fixed by some method, so it can't deflect. According to Solidworks, the bracket survives with flying colors, but it bothers me that I...

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What I understand is, I have written something like this myself. What is a Static Proxy and a Dynamic Proxy then? Also, What is a Transient Proxy and a Persistent Proxy?

I solved this question correctly, however I have a question regarding how I should work with the weight of the firefighter climbing the ladder. When drawing the force diagram for this problem, I should only include forces acting on the ladder, right? Which means I would represent the normal...

Can anyone explain why an artificial magnetic field may or may not promote an increase in cellular metabolism?

Since electrical charges causes a sparkle or a crackle which is light and sound. Also light and sound are forms of energy does that mean that electrical discharge releases energy and if yes then the release of energy have an effect on charge

Hello, Let's imagine we have an infinite plane (or large enough compared to the region of interest and measurements) pierced in normal direction by magnetic field B which is uniformly distributed but time varying. For the sake of simplicity we'll presume the magnetic induction is linearly (and...

Consider a block on a sheet of paper. If the sheet is pulled without sliding the block, who has done work on the block (since it has undergone a kinetic energy variation)? I can not see another force doing work other than the static frictional force on the block.

a) Answer that I found: 56.31 degrees b) Answer that I found: 121.71 Kg For b) not sure if I need to add the 20 N and 5 N to the total of the cargo mass.

Would it be possible for photons to form some sort of static structure, like a standing waveform, if space-time was curved enough? It seems like a structure like this exists around black holes. Is there any other distortion or phenomenon that could cause this, such as a neutron star or a galaxy?

The videos from Veritasium explaining permanent static magnets and electromagnets were quite good I thought… But they have me a little confused with regard to the origins of magnetic fields generated by an electric current as opposed to a permanent static magnet from say iron. 1. An...

Homework Statement There is a square loop with mass of 4.0 kg and side length 4.5 m that is tilted upwards from the ground at a 25 degree angle with one side resting on the surface. The loop is a conductor that has 25 A of current going through it. The question asks to find the strength a...

Greetings, I'm an Undergraduate Mechanical Engineering student. I want to design bolted joints on Figure 1, I'm trying to perform a basic static analysis of the structure to understand the forces acting on its members and its current stress state. I've included dimensions and position of its...

Hi. This picture shows an iron ring shielding a static magnetic field: Does this really work, and why? I know that a conductor can shield an electric field (Faraday cage) and a changing magnetic field (Lenz's law), but why would it shield a static field? Especially since iron is a ferromagnet.

Homework Statement https://imgur.com/v13K6sE a uniform rod of mass m is placed as shown, with one of its end resting on a smooth wall while 1/4 of the rod's length is sticking out of a rough table. Find the net force the table exert on the rod at the corner. Homework Equations i drew the free...

Homework Statement The static friction coefficient on an inclined plane is equal to tan(θ). The problem requires me to prove this also works by using an x-axis parallel to the ground rather than parallel to the incline. I understand how to get tan(θ) using the incline as the x-axis, but I don't...

I started having this problem with wearing slippers (or any shoes with rubber soles) in the house because the rubber, rubs the carpet and charges me up. Anything metal that I touch gives me a mild-nasty shock depending on how charged up I am. I tried different kinds of slippers and socks, I...

I teach aerodynamics and I’m looking for a way to explain how d and s pressure are related. I understand that as dynamic increases static decreases with the total sum remaining the same. With dynamic being zero the total goes to static. As dynamic increases the static pressure decreases...

Homework Statement The equation of motions of a series of pendulums coupled by a torsion spring is this: ##\ddot{\Phi_i}=-\frac{k}{ml^2}(2\Phi_i-\Phi_{i-1}-\Phi_{i+1})##, where k is the torsion spring constant, m is the mass of a single pendulum, and l is the length of a single pendulum. We...

Has anyone read the book of this author? What is your opinion about this topic? https://www.google.de/search?q=tired+light+lyndon+ashmore&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjbo_exj5vfAhXK2qQKHdHsD6AQ_AUIDygC&biw=1280&bih=623

I was wondering how spacecraft s discharge when encountering van allen belts (for example the juno spacecraft around jupiter) since obviously there is no earthing and is it possible to remove excess charge to power something on the craft?

Homework Statement The goal is to calculate the static forces in the throwing arm of the trebuchet when it's pinned as shown in the image. The counterweight is equal to 1435 Newtons. The mass of the arm is equal to 114 Newtons. Dimensions are shown in inches. The pin is in double shear...

As is known, when calculating localized states in a crystal it is roughly considered that the point charge is “immersed” on medium with static dielectric constant ε. However, a simple estimate, for example, shows that an impurity atom with charge modulo equal to the electron charge creates at...

Homework Statement a) If the distances ##s_1## and ##s_2## are the amounts the springs are streched while in static equilibirum, Write down the static equilibirum equations. b) When the system is distrubed from its equilibirum state, both mases move vertically. Let ##y_1(t)## and ##y_2(t)##...

Maybe stupid question but it confuses me:) For Example engine produces 100Nm of torque at 3000RPM. So that's mean that this 100Nm at 3000RPM in this particular moment is static force? Because torque doesn't move anything. If it start to spin, it doing work and work over time is POWER. (~43Hp at...

Homework Statement How would the motion of the block look like when the Force of kinetic friciton is more than the Limiting value of static friction? Homework Equations Kinteic Friciton=μN The Attempt at a Solution I think the block after overcoming the limiting value of static friction will...

Homework Statement A uniform cylindrical wheel of mass ##m_{1}## and radius ##R_{1}## rotates with angular velocity ##\omega_{1}##. It lies a certain distance (along the same axis) from a static wheel of radius ##R_{2}## and mass ##m_{2}##. The wheels are then pushed against each other with a...

Homework Statement Homework Equations Σtorque = 0 Σfx=0 Σfy=0 torque= F r sinθ (θ is the angle between the r and the F)The Attempt at a Solution OKay, now i know how to solve this, but it's like i asked myself, how to know if this is a question that i am supposed to use Σfx=0 and Σfy=0...

Homework Statement [/B] 2. Homework Equations Fs = Nμ W = mg Fy = Fsin(θ) Fx = Fcos(θ) The Attempt at a Solution [/B] Hello all at PhysicsForums, I have a question on angled force and static friction. From my attempt below, I think I have found the maximum force required and would need...

Homework Statement A large box of mass M is moving on a horizontal surface at speed v_0. A small box of mass m sits on top of the large box. The coefficients of static and kinetic friction between the two boxes are μs and μk, respectively. Find an expression for the shortest distance dmin in...

Homework Statement [/B] A child sits on a sled (50kg) on a snowy hill with an incline of 5 degrees. The coefficient of static friction is 0.05. What downward force must a parent apply parallel to the normal force, to prevent the child from sliding down the hill? (Answer: 366N)Homework Equations...

I just googled to see if this was a known thing and saw there was a closed topic on the subject. Usually I like to think of myself as a creature of logic and love to point out when other people distort reality to support their emotions but now I am all alone and trippin' about what follows. For...

Hi, i am trying to trying to solve this question as this question is slightly different from the usual type of overhanging question. Please advice on the approach. Thank you I have to find the maximum overhang possible, l, before the whole blocks falls apart

I heard that the average professional boxer's force of punch is between 500-750lb. If the coefficient of static friction of rubber (from shoes) to say concrete is at most 0.85 then why can boxers get hit (especially in the chest) without losing footing? Does it have something to do with the...

Ok, so assume we have a wheel on the road traveling to the left. The wheel spins CCW and also has translation to the left. If we let the wheel roll, assuming no slip, then the translation velocity to the left will counteract the rotational velocity to the right at the bottom of the wheel, so...

Homework Statement The figure below shows a metal object (2) hanging by a thin cord from a floating wooden block (1). The wood block has a SG of 0.3 and dimensions of 50mm x 50mm x 10mm. The metal part as a volume of 6600m^3. Find the mass of the metal part and the tension in the cord. Work in...

How do i suppose to determine the uncertainty for the slope of my Static friction against normal reaction graph? My data for static friction and normal force has the uncertainty of +/- 0.0001 The uncertainty is too small for me to draw airbox/bar in the graph to draw the max and min slope...

I am currently working on designing a linear brake/lock for a completely different purpose but it will be based on the same principle as in a quick clamp shown below. Before building a prototype I do want to make some rough calculations to check dimensions, angles etc. etc. However, I am for...

Homework Statement Homework Equations maximum torsional shear stress = (Torque*radius)/polar moment of inertia The Attempt at a Solution I am lost on equation(4-14), I looked through the textbook but didn't find a derivation.