Static friction Definition and 507 Threads

Homework Statement A car traveling on a flat (unbanked), circular track accelerates uniformly from rest with a tangential acceleration of 1.70 m/s2. The car makes it one-quarter of the way around the circle before it skids off the track. From these data, determine the coefficient of static...

So if I compare how the accelerations are observed in two objects, a car and a block, both having the same mass of 100kg on a surface with μ_{s} = .5 and μ_{k} = .1 Car: The car will have Static Friction Force f_{s} = μ_{s}F_{N}=[μmg = ma] = [.5(100kg)(10m/s^{2}) = 100kg(a)] => so...

Hello, I'm trying to reconcile what seems to me to be a contradiction. Last week, I did a lab experiment where we stacked some metal bars in a tray and measured the force required to pull the tray into motion and break away from the force of static friction. As we predicted, the more mass we...

Doubt - Force cannlt exceed limiting friction for a block to remain at rest on ground. However for to blocks to move together, it becomes more than limiting friction, yet only static friction is acting on the blocks? Which moves the lower block. How can it be more in this case? Relative...

Homework Statement the maximum force is F=F1 +F2 + T as shown in the textbook... I can't understand why the tension of spring is also = F1...Is it because of the writer assume the spring is directly attached to the part P (upper part of the block) ?? Homework EquationsThe Attempt at a Solution

Homework Statement An ideal cord is connected to a wall on the top of an inclined plane at one end and is wound around a thin homogeneous cylinder of mass M and radius R. The inclination angle is ϑ and the static and dynamic friction coefficients between cylinder and plane are μs, μd , and the...

Homework Statement Today we were studying a block on an incline and determining the angle needed for the block to start sliding. The question asked is: Why is the equation for the coefficient of static friction independent of the weight of the block? Homework Equations ΣFx=Fapplied-fs=0...

Homework Statement Calculate the force of friction on a toy car as it rolls across a flat floor. Given: mass = 0.293kg time = 3.66 s displacement = 8.7Homework Equations Fnet = mass x acceleration displacement = [(velocity1 + velocity2)/2] time velocity2 = velocity1 + acceleration(time)The...

Homework Statement The sports car ) is rounding a flat, unbanked curve with radius R . If the coefficient of static friction between tires and road is Us, what is the maximum speedat which the driver can take the curve without sliding? why in this problem i am given Static fiction coefficient...

Homework Statement The uniform 14-ft pole weighs 150 lbs and is supported as shown. Calculate the force P required to move the pole if the coefficient of static friction for each contact location is 0.40. (Sorry for the sideways images!) [/B] Homework Equations 1.) Fmax = μs*N 2.) ∑M = 0...

Hi, Please explain what is the difference b/w kinematics friction and static friction ? Please explain, what is rolling friction ? Is it when we are pulling a weight with rope, and rope is rolling on a wheel ? for example in past days, people used rope to get water from well. Please explain...

If smooth rolling motion does not necessitate static friction, which I have been led to believe by a certain @haruspex , then what other forces or principles could prevent a smoothly rolling body from slipping?

Homework Statement Samantha and Rebekah each push on a stack of doughnuts equally. If the coefficient of static friction is .28 and the box has a mass of 18kg, what force does each push individually to break static friction? Once it's moving, the coefficient of kinetic friction is .17, how much...

Homework Statement So, I need to figure out the coefficient of static friction using the equation tanθ = µs ONLY. I have been given the angle 26 degrees, and a mass of 424.32g. Homework Equations tanθ = µs[/B] The Attempt at a Solution I don't know where to start...

Hello, members. What are static, limiting, kinetic, rolling frictions and sliding frictions? I'm unable to grasp what exactly the difference is. Could somebody give me an example that covers all of them (or some other example that could easily tell me the difference) so that it can be easy for...

Homework Statement A 60-kg person rides down an icy hill of 20° slope while standing on a 3.0-kg flat-bottomed bathroom scale. Assume there is no frictional force between the bottom of the scale and the hill. The static friction force the scale exerts on the person is Homework EquationsThe...

Homework Statement Homework Equations Fs = μ FN The Attempt at a Solution Ok, so I drew a free body diagram and tilted it 90 degrees so that Fg of the small box points right and Fstatic points left. Fg = 4.7 kg x 9.8m/s2 = 46 N we want Fs to equal 46 N , correct? so we use the formula Fs...

Homework Statement A glass of orange juice is on the floor of a subway car traveling along a straight path at constant velocity. The coefficient of static friction between the glass and the floor is 0.32. The subway suddenly accelerates forward. What is the maximum acceleration that the subway...

I want to know why Static friction∝normal reaction and Why not Static friction∝ area of surface Static friction∝weight

Homework Statement A 2 kg block rests on an inclined plane with an angle of 30. A force of 5 N is applied to the block in a direction down the incline plane until the block begins to move when the force reaches 7.3 N, what is the approximate coefficient of static friction between the block and...

Homework Statement The cylinder in the drawing weighs 100[N]. there is a horizontal rope at the top that prevents it from rolling. what is the coefficient of friction if it's on the verge of movement Homework Equations Friction force: f=μN The Attempt at a Solution The whole weight of the...

An air-track glider of mass 0.100 kg is attached to the end of a horizontal air track by a spring with force constant 20.0 N m (Fig. 6.22a). Initially the spring is unstretched and the glider is moving at 1.50 m s to the right. It is calculated that with an air air track turned off, a glider...

Homework Statement A block of mass m is at rest on an inclined plane of angle θ with respect to the horizontal. There is friction between the block and the inclined surface (μk and μs). Now, assume that the value of θ is less than the value in part A) (so that the block will remain stationary...

Homework Statement A bowling ball rolls without slipping up a ramp that slopes upward at an angle β to the horizontal. Treat the ball as a uniform solid sphere, ignoring the finger holes. Explain why the friction force must be directed uphill. Homework Equations F=ma, torque=I(alpha)...

Homework Statement There is a box that has a mass of 30 kg. The coefficient of the static friction is 0.75. Find the horizontal force. Homework Equations Fs=muFn F=ma The Attempt at a Solution Fs=(.75)(.98)(.30)=.2205 N That is probably way off... I am very confused right now. Could someone...

I don't really have a specific problem, but for example, I was doing a problem where a constant force unwounds a spool of wire (a disk). The force pulls at the top of the disk to the right and the force of static friction is also at the bottom to the right, the same direction as the sphere is...

I have to make 2 ramps of 30 cm long along with 2 objects(objects need to be 8 cm long). One must be slippery so that it has a low coefficient of friction and one needs to be sticky and have the highest coeffivient of friciton possible. Bassically we place object on ramp raise it from one side...

Homework Statement A ladder,10 m long and having a mass of 25 kg, rests on a rough horizontal floor and is supported by a rough vertical wall. The ladder is inclined at 60 degrees as shown and starts to slip when a person having a mass of 75 kg has climbed halfway up it. The coefficient of...

Homework Statement I got this problem: A wedge of mass m = 36.1 kg is held in place on a fixed plane that is inclined by an angle θ = 21.3° with respect to the horizontal. A force F = 302.3 N in the horizontal direction pushes on the wedge, as shown in Figure 4.25a. The coefficient of kinetic...

Homework Statement I'm trying to understand how static friction opposes the motion of a moving car. From what I have read, the car tyre doesn't move relative to the ground. The car tyre pushes on the ground and the ground pushes back - this is how the car moves. The force of friction is in the...

[b]1. Problem I am currently doing a home experiment about the coefficient of static friction. I've set up a ramp and am testing at which angle a tissue box begins to movie (with five different masses in it)... Although for every mass I use the angle seems to remain the same. The angle at...

I am confused with the wording for a static friction problem; this particular wording also lead me to a conceptual question on the force of static friction. It all started with a question in my textbook that I figured out how to solve for the right answer. The question states, a box of m is...

i am having some trouble figuring this out I can not figure out which formula to use i have tried Mass x G x Static Friction which resulted in 1 x 2 x 9.8 = 19.6

Hello, I hope someone can help me with this question. "Design a simple experiment that you could carry out in your home to i) determine the coefficient of static friction between an object and a surface. ii) prove that the coefficient of static friction is dependent only on the surfaces in...

Homework Statement block is placed on a ramp at an angle of 39.4 and height of the ramp is 1.610m and the mass of the block is 8.54kg if coefficient of kinetic friction is 0.111 and the coefficient of static friction is 0.173 what is the speed of the block at the bottom of the ramp. if it...

In a recent physics class I took, my teacher explained how friction is not affected by surface area, but by the "bumpiness" of the two objects and the mass, as well as other things, but not the surface area. But this made me wonder how nails get harder to pull out the deeper they are embedded in...

I have read that static friction does no work and energy of the system is conserved if only this type of friction exists. Is this only an experimental fact, or can it be proved from basic principles? If it can, how?

Homework Statement Static friction can never do work on an object. a. True b. False Homework Equations The answer is False, indicating that static friction can do work. The Attempt at a Solution W=fd, when d=0 w=0 regardless of the force. How does this work? Or is the online...

Homework Statement A box rest on an incline making a 34 angle with the horizontal. It is found that a parallel force to the incline of at least 235 N can prevent the box from sliding down the incline. If the weight of the box is 800 N, find the coefficient of static friction between the...

Homework Statement 4.00-kg block rests on a 30.0° incline as shown in the figure. If the coefficient of static friction between the block and the incline is 0.700, what magnitude horizontal force F must act on the block to start it moving up the incline? Homework Equations F=ma...

1. a 5.0 kg block is pushed up a wall by a 90N force. Assume that the block starts from rest and that it has an acceleration of 0.5m/s^2. a. find the coefficient of kinetic friction between the block and the wall. b. Find the work done by each force acting on the block. c. Find the...

Homework Statement The problem reads : You are riding your motorcycle one day down a wet street that slopes downward at an angle of 20 ∘ below the horizontal. As you start to ride down the hill, you notice a construction crew has dug a deep hole in the street at the bottom of the hill. A...

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 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...

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...

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...

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 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...

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...