Static Definition and 1000 Threads

Homework Statement Find height (h) of the water level which can result in failure of dam by tipping it over due to water pressure at U/S of dam. Also draw the free body diagram. Density of water to be = 1000 kg/m^3 and its specific weight=62.4 lb/ft^3 Hints: The specific weight of concrete is...

Homework Statement Two uniform, 75.0-g marbles 2.00 cm in diameter are stacked as shown in Fig. P11.75 in a container that is 3.00 cm wide. (a) Find the force that the container exerts on the marbles at the points of contact A, B, and C. (b) What force does each marble exert on the other...

Hi everyone, Is there any mechanism/method/device to control static pressure? Noting that, total pressure = static + dynamic pressure. The scenario I am thinking is just water flowing through a pipe (assume incompressible), and I want to control the static pressure at two points along the pipe...

in my physics lab we did an expirement where we had to use an vernier electrostatic kit. So it consisted of placing a metal can inside a metal cage, and both were attached to an plastic disk, and below was a metal plate which was used for grounding. A black wire was connected from the cage to...

Homework Statement "When the three blocks in Fig. 6-29 are released from rest, they accelerate with a magnitude of ##0.500 \frac{m}{s^2}##. Block 1 has mass M, Block 2 has mass 2M, and Block 3 has mass 3M. What is the coefficient of static friction between Block 2 and the table?" Homework...

I think this is the place to ask these questions about static resistance of semiconductors: The static resistance in semiconductors is that kind of resistance that will decrease if the semiconductor is more heavily doped, right? In transistors, and especialy saturated transistors the usual 0,2V...

What temperature does thermocouples show? Static or Total? And also in formulas for example Q(dot) = m(dot) * C_p * (T2 - T1) which temperature should be used precisely?

Homework Statement A block of mass ## M_1 ## is on an inclined plane (the plane is inclined at 30 degrees), and is attached with a light cord over a light, frictionless pulley to another mass ## M_2 ##. ## M_1 ## is fixed at 5.00kg, and ## M_2 ## can be varied. When ## M_2 = 3.20 kg ##, ##...

Homework Statement I drop a 50mm sq concrete cube fom a notional tower into a steady horizontal wind stream of 10m/sec. Homework Equations How long before the cube reaches the wind spead What is the accelleration How far will the cube have traveled down range The Attempt at a Solution

Hey all, I'm currently working on a problem where whether an upright vessel will be knocked over by wind needs to be determined. The vessel is essentially an upright cylinder with a skirt on the bottom. I've attached a link to a blank diagram of it. I know how to calculate the force from the...

Equations: Net torque=0=Net force I believe this is a static equilibrium question but can't figure out how to do it

as far as I know this is real, from Scotland. could be a good discussion starter for static electricity;

I have two surfaces that have a coifficent of friction of .6. Disregarding mass (if possible) at what angle would the force of static friction and the normal force be equal

Homework Statement The attachment above contains the diagram given in the problem M1 = 25kg M2 = 35kg Friction coefficient between M1 and stucture = 0.15 Friction coefficient between M1 and M2 = 0.25 Friction on pulleys and mass on pulleys is negligible. Find the minimum mass M3 for sliding...

at the beggining of basic mechanics, we learned about friction, moreover we distinguish between static and dynamic friction. there is something quite disturbing: when an object on an inclined rod is static we can say that the static friction is holding it in place. now, whe we push the object up...

Need some information about electret. Is it possible to charge a metal plate electostatically using electrets. will electrets attract neutral charged things, like glass rod attracting paper pieces after rubbing with wool ?

Hi Everyone, I'm trying to justify to myself why |F(a)| > |F(b)| > |F(c)| I think I can see why |F(b)| > |F(c)| due to special relativity case c observed from the charges point of view would observe the charges closer due to lorentz contraction. As the charge is invariant would result in...

A (possibly stupid) static electricity question: Person A is carrying an electrostatic charge. They touch person B, both get a shock. If both persons were off the ground(eg hanging from ropes) ...would they still get a shock?

Homework Statement truck moves at 22,5 m/s On board the truck, behind, is a box. the static friction coefficient for the box, is 0,250 with regard to the friction between truck floor and the box floor. calculate the shortest possible stopping distance, such that the box does not slide at...

Homework Statement I am trying to prove that the coefficient of static friction is equal to the tan of the angle of incline. (You can find the proof of this from ) I set the angle of incline as my independent variable and had an angle range from 10 to 37.5 degrees. After setting the slope to...

Homework Statement Two boxes each weighing 900 N are stacked on a horizontal floor. Box A is on the bottom, box B is on the top. The coefficient of static friction between box a and the floor is 0.3. A worker applies a force of 600 N to box b parallel to the floor, and the stack moves together...

Homework Statement Homework Equations sum of torques = 0 The Attempt at a Solution So I tried to put the torques into the equation: Sum torques = mgL - T *sin(theta) * (L-x) = 0. Solving for the T gave me [mgL]/[ (L-x) * sin(theta) ]. This is not an option in the answers. Could anyone...

1. Homework Statement problem is above Homework Equations sum of torques = I * angular acceleration = 0 for rotational equilibrium The Attempt at a Solution OK, here's what I tried to do. I wrote sigma Fy = Fleft pier up + F secondleftpierup - Fg,beam = 0 I assumed that the two piers have...

Hi all, I am very confused by this concept. As I searched online, all respondents say that friction decreases as angle increases because normal force decreases. BUT, they don't explain this phenomenon: A block on a ramp is static at certain angle, and after the ramp is raised by a certain...

Homework Statement Suppose we have a folding ladder, so that when its legs are spread it makes an isosceles triangle. Suppose it has a support that runs parallel to the ground. There is a bucket of paint that rests on top of the ladder, and the mass of the ladder is negligible. Data: The legs...

I wanted to know what formula's do I need to figure how much force is required to make a dent in a car. I am then placing a bumper guard made up of carbon fiber, and wanted to know what equation do I need to use to figure out how much force is required to make a dent with the carbon fiber bumper...

In a situation like this, there are two equilibrium's, For just about to accelerate downwards: mgsinθ - Ffriction - T = 0 For just about to accelerate upwards: T - Ffriction - mgsinθ = 0 Is there a situation where there is no static friction i.e. when mgsinθ = T?

Homework Statement The figure below shows a light truss formed from three struts lying in a plane and joined by three smooth hinge pins at their ends. The truss supports a downward force of = 1 330 N applied at the point B. The truss has negligible weight. The piers at A and C are smooth. The...

Homework Statement There is a diving board held up by two pillars A and B, and there is a diver standing on it's edge. What are the directions of the forces exerted at points A and B? Picture Below: Homework Equations F_NET = 0 T_NET =0 The Attempt at a Solution I thought both A and B were...

Homework Statement Homework Equations Fr (resultante force) = 0 Sum of all forces aplied at the strut = 0 Sum of the torque of all forces = 0 The Attempt at a Solution I started by analysing the torque, since the strut is on static equilibrium and I ended up having C (tension on the cable)...

Here is the rub. Most of the online sources and in a kind of statement in my book says that we gain a negative charge when we rub our feet on the carpet. So when we touch a door knob we get a electric shock because the electrons is transferred from us to the door knob However, Shouldn't it be...

Hello, I am reading through some GR lecture notes and have come across the following: "A spacetime is static if there exists a coordinate chart where: ∂0gμν = 0 g0i = 0 This spacetime admits a Timelike Killing vector X that satisfies: X[α∇βXγ] = 0 " How do I go about proving that this...

Homework Statement A disk roll without slipping down a incline plane. Identify the forces acting on the disk, explain qualitatively which of these forces do work. Homework Equations The rotational work is given by W=\int \tau_z d\theta (1) , where \tau_z is the component of the torque...

Could you perform Static structural analysis on this solid sphere? No contacts to be used. I do not have any specific boundary conditions(unable to apply constraints to a complete solid spherical body) All i know is the pressure that needs to be applied. You could consider a smiley ball on...

I have a doubt regarding the definition of rotational work, which is as follows W = \int \tau_z d \theta Where \tau_z is the component of the torque parallel to the axis of rotation z. My doubt concerns the fact that, looking at this definition, it seems that any torque which has an axial...

Homework Statement You are holding a sign as shown below. The sign (including the horizontal bar it hangs from) has a mass of 2.20 kg and is 40.5 cm wide. The sign is hanging from a 1.03 m tall, 4.46 kg vertical post. The sign is symmetric with a uniform mass distribution as implied by the...

The code [FONT=Consolas] is supposed to generate 0 1 2 My question is this: If we declare $x = 0 in the function then why doesn't it reset to 0 every time we run the function? -Dan

Homework Statement A 1790N force pull a 266kg load up a 17º incline. what is the coefficient of static friction between load and incline. Homework EquationsThe Attempt at a Solution Tried several times on notebook but I haven't seemed to solve the problem.

Homework Statement You are trying to slide a sofa across a horizontal floor. The mass of the sofa is 200 kg, and you need to exert a force of 350 N to make it begin to move. a) Calculate the coefficient of static friction between the floor and sofa b) after it starts moving, the sofa reaches a...

Hello! In this thread, in this answer, my statement "A time-varying electric field creates a magnetic field which is time-varying itself" was refuted. Because I never observed this before, I would like to discuss about it. As far as I know, Maxwell's equations are valid always together, that...

Homework Statement I have 3 masses (Fα, Fβ & Fg) with 2 pulleys, and a wind variable which is in static equilibrium. I have already calculated the appropriate forces for the 3 masses by multiplying it with 9.81m/s² (gravity). Fwind = 60N Fα = 313.9N Fβ = 619N Fg = 882.9N I'm required to find...

Homework Statement A 500 kg ox runs and speeds up by 3 m/s2, but is held back by a 120 kg plow that is attached to its back. Assuming the coefficient of static friction between the horse's hooves and the soil is 0.73, what is the magnitude of the static friction force the soil exerts on the...

Homework Statement A 70-kg skier is in a tuck position and moving down a 20-degree hill. Air resistance applies a resultant force of 15 N against the movement of the skier. The coefficient of friction between the skis and the snow is 0.09. What is the resultant downhill force acting on the...

Its for my final project. We are doing a sliding a textbook down an *incline plane* and we are expected to find coefficient of static friction without using Newton guage, and we are also now allowed to use kinematics. I just need some infomration on how to do this, like a formula or something in...

When a body is in motion , does kinetic and static friction act simultaneously

Homework Statement It's been a little while since I did one of these. My question is: We have to use http://phet.colorado.edu/sims/mass-spring-lab/mass-spring-lab_en.html to find the measurement of k, the spring factor using two different methods. For the method I am looking at, is the static...

Homework Statement If you have 2 boxes over each other in a car that is slowing down . The mass of each one of them is 10kg and Us = 0.4 for all surfaces. What is the maximum deceleration that doesn't make the boxes fall? And will it make different if you change the masses of the objects? 3...

Hi everyone This is my first post on the forum. I work in engineering and use this forum to answer questions from time to time. I am looking for confirmation of my understanding of static rotation torque (not something I deal with in day to day work). Imagine 2 identical discs or washers that...

Hi, I did some search on Static Cling products like decals . They work using a static charge concept. But static charge can easily be grounded and cause the charges to be neutralized. So, why is it that static cling products do not lose their static effects? Any ideas? Thanks for reading...

I have spent quite some time trying to get this, can someone please help me understand this? A plank is being pulled by a constant force F, it rests on top of two identitcal sylinders - there is rolling without slipping. What I don't understand is, why does F(p) - red arrow force, affect the...