Friction coefficient Definition and 123 Threads

Homework Statement A skier is sliding down a 20o slope at constant speed, what is the kinetic friction coefficient? Homework Equations E = 1/2 mv2 W = Fd F = ma F = μN = μmg The Attempt at a Solution Attempted to use ma = μmgsin20, which crosses out the masses since mass was not given, but...

Homework Statement The cylinder weighs 200[N] and lies on a rough surface. a rope holds it in place. What's the tension T in the rope and what's the minimal coefficient of friction. Homework Equations Friction: f=μN The Attempt at a Solution All the geometry i have drawn. T balances the...

Hi all, I need to calculate the friction coefficient between road and the tyre of the car. I came across few answers like which solves as from the following torque equation. Engine torque = braking torque + acceleration troque + Inertial torque + drag torque + rolling resistance. For...

I am using the tyre friction equation Fc=mu*Fnormal to calculate the downforce required for each corner of the Gilles Villeneuve circuit in Canada. Fnormal composes of the downforce and weight of the car. mu has a maximum value of 1.7, however this value will vary from corner to corner right...

Homework Statement A man standing in the corner of the wall tries to climb up by pushing against both the walls, if the friction coefficient between the wall and his elbow is 'u' , then find the minimum force from which the man must push against in order to climb up the wall, given that he...

Homework Statement Benjamin (4 years, 18 kg incl sledding) is at the top of a hill run which has slope of 20 degrees to the horizontal and the length 15 m. Slope followed by a large horizontal surface. Benjamin embarks straight down the hill, gets speed and just when he reaches the...

Hi Guys, Just wondering if anyone knows of the friction coefficient of Mud? i am designing a device that gets pulled through fields of thick grass and mud. And i am wanting to know what the friction coefficient of Mud would be so i can calculate the maximum frictional force on the device...

In a recent lecture,I learned that the friction coefficient "mu" between the tire and road surface is determined experimentally by using a graph. i.e a graph between the longitudinal tire force and the longitudinal slip. Well,how did engineers emperically arrive at such a graph in the first...

Homework Statement A block is projected up an inclined plane that makes an angle θ to the horizontal. It returns to its initial position with half its initial speed. What is the coefficient of kinetic friction between the block and the plane in terms of the angle of the incline...

Homework Statement There are 2 questions in the attachments both with the same scenario I'm having troubles with. Homework Equations f=ma The Attempt at a Solution I tried finding the budging force between the 2 masses and that was about 4. I don't know where to go from there to...

Consider the system: A block of mass M is placed on a level table and connected to a mass m by a light string running through a pulley. If mass m is released, it will start to fall and the wooden block will be pulled across the table. Prove that the kinetic friction coefficient can be given...

Homework Statement (see attachment) Homework Equations The Attempt at a Solution I am not able to understand the question and build a scenario in my mind. The question asks the distance traveled when the cylinder starts slipping. I can't think of the situation when the cylinder...

Homework Statement A 0.5 kg wooden block is placed on top of a 1.0kg block. The coefficient of static friction between the two blocks is 0.35. The coefficient of kinetic friction between the lower block and the level table is 0.2. What is the maximum horizontal force that can be applied to the...

Homework Statement A skier skiing downhill reaches the bottom of a hollow with a velocity of 20m/s, and then coasts up a hill with a 10° slope. If the coefficient of kinetic friction is 0.10, how far up the slope will she travel before she stops? Homework Equations aΔt=v2-v1 d= 1/2(v1 +...

I've got the following exercise, which I've done 3 times already and I think I haven't made any mistake: A body is slid upwards through an inclined plane of angle \theta=15\degree. Determine the friction coefficient of the body with the surface of the plane if the time it takes to go upwards t_a...

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 25.0 kg block is released from point A (on a ramp, think of a skateboarders half pipe) at 3.00 meters. The track is frictionless except from points B to C (which has a length of 6m). The block travels down the track from point A to B, at which point it hits the friction...

Homework Statement A 65-kg speed skater with a velocity of 15.0m/s comes into a turn on the track of radius 25.0m. a) How much friction must be exerted between the skates and the ice to negotiate the turn? b) Determine the coefficient of friction between the skates and the surface of...

Hallo, does anybody knows where to get friction coefficients for different materials used in design (PTFE; PP; PVDF; PFA; TEFLON; VESPEL) or how to calculate them? Suppliers do not give a lot of data,..is there a theory behind to estimate friction coefficient? thanks in advance!

The data came from my lab involving friction between wooden block with metal weight on it and a metal table. The wooden block is moved from rest and the force is measured using a force meter and Logger pro. Homework Statement Force of peak static friction = 23.285N. Normal force is...

Homework Statement from giancoli 5th ed (algebra based) chapter 4, question 42 Drag race tires in contact with an asphalt surface probably have one of the higher coefficients of static friction in the everyday world. Assuming a constant acceleration and no slipping of tires estimate...

Homework Statement At a construction site, a small crane is raising two boxes of nails on a plank to the roof. One box has already been opened and is half full, while the other box is new. The boxes, including the nails, weigh 10kg (box 1) and 20kg (box 2), respectively and are both the same...

Homework Statement m = 10kg static friction coefficient (Us) = 0.4 angle = ? Homework Equations If the coefficient of static friction is 0.4, calculate the angle at which the box begins to slide down the plank as it tilts. The Attempt at a Solution m = 10kg Us = 0.4 angle...

Homework Statement A train is traveling at 3.73 degree incline at a speed of 3.25 m/s, when the last car breaks free and begins to coast without friction. (i) How long does it take for the last car to come to rest momentarily? (ii) How far did the last car travel before (momentarily)...

Homework Statement A pig is sliding down a ramp that has an angle of 35 degrees from the horizontal plane. If the friction coefficient was 0 the ride would only take half the time. What is the kinetic friction coefficient between pig and ramp?Homework Equations Fnet = ma v² = u² + 2as a =...

The coefficent of static friction between the floor of a truck and a box resting on it is 0.40. The truck is traveling at 82.9 km/hr. What is the least distance in which the truck can stop and ensure that the box does not slide? No idea where to even start...

Homework Statement Two blocks with the same mass m = 1 kg are stationary on two slopes with slope angles of 30 and 45 degrees. Both blocks are connected with the larger one in the middle via two pulleys. Made a sketch to make it clearer...

hello, I 'd like to know the static/kinetical friction coefficient between rubber- steel (the most commonly used), I searched the internet but whithout succes the application is: a conveyor belt that makes contact with a troughing roller) anyone can help me ? thank you !

Homework Statement A 22kg box is being pulled across a flat surface by a rope at a 25 degree angle with the floor. What is the kinetic friction coefficient? Homework Equations (Fnet)y= -mg + Tsin() + n(normal force) (Fnet)x= Tcos() + kf The Attempt at a Solution I cannot...

hi.. may i ask what is the relationship(formula) between the viscous friction and the frequency? if i know the value of k(spring constant), M(mass), and f(frequency), am i able to find out friction coefficient, b?

Hi guys, I got this thought in my head. If I have a box of mass x, being pulled towards East and the angle \theta, then force applied to the box in order to move it on the surface with friction coefficient \mu has to be in such a way: My question is... wouldn't N be: Or, N...

Homework Statement To test the performance of its tires, a car travels along a perfectly flat (no banking) circular track of radius 412 m. The car increases its speed at uniform rate of, at= 4.14m/s^2, until the tires start to skid. If the tires start to skid when the car reaches a speed of...

Homework Statement Blocks A and B have mass of Ga and Gb respectively. Wire has no mass, it starts moving so that B has constant speed downward Homework Equations 1.Find μ (frictionkoeficient) regarding GA og GB. 2.When system start moving a cat with weight Ga jums on block A and system...

Homework Statement A force, F, applied to a 12.1 kg crate at an angle (theta) of 41.0 degrees makes the crate move horizontally with a constant acceleration of 1.85 m/s^2. The coefficient of kinetic friction between the crate and the surface is uk=0.35. Calculate the magnitude of F...

Hello everyone Do you know approximately the friction coefficient in drawer slides? I am going to use it in a robotic mechanism. Thanks

A light horizontal spring has a spring constant of 108 N/m. A 3.05 kg block is pressed against one end of the spring, compressing the spring 0.111 m. After the block is released, the block moves 0.204 m to the right before coming to rest. The acceleration of gravity is 9.81 m/s2 . What is...

Homework Statement A 2.00 kg block situated on a rough incline is connected to a spring of negligible mass having a spring constant of 100 N/m. The block is released from rest when the spring is unstretched, and the pulley is frictionless. The block moves 0.204 m down the incline before coming...

I want to find the coefficient of friction. could you pls provide me how to determine the friction coefficient for journal bearing. It is urgent..

*SOLVED* Homework Statement Figure shows a block of mass m resting on a 20 degree slope. The block has coefficients of friction \mus=0.80 and \muk=0.50 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg. What is...

Homework Statement A 4.94 kg block located on a horizontal floor is pulled by a cord that exerts a force F = 12.1 N at an angle θ = 15.0° above the horizontal, as shown in the Figure. The coefficient of kinetic friction between the block and the floor is 0.100. What is the speed of the...

Homework Statement What is the maximum speed with which a 1200 rubber-tired car can take around a banked curve with radius of 80.0 meters an angle of 19.0 degrees? (static friction coefficient is 1.0) Homework Equations Fs=mu*F(normal) F(netxdirection)/m=acceleration...

Homework Statement A block is at rest on a plank whose angle can be varied. The angle is gradually increased from 0 deg. At 26.5°, the block starts to slide down the incline, traveling 3.10 m down the incline in 2.00 s. Calculate the kinetic coefficent of friction between the block and the...

Homework Statement A block slides down a frictionless hill, h=1.8m high. At the top of the hill the block has a speed of v=2.8m/s. At the bottom of the hill, the block travels over a patch of rough pavement and comes to a complete stop after s=5.0m distance due to friction. a) What is the...

Homework Statement Here is a picture of the problem I am trying to solve in a book. The problem I am having trouble with is #4 (the solution is provided in the brackets below the question -> 0.432) http://img15.imageshack.us/img15/241/questiona.jpg Homework Equations F=ma Ff=uma etc...

Homework Statement What is the minimum coefficient of static friction necessary to allow a penny to rotate without sliding off a 33.5rpm record (diameter of these old-fashioned records is 0.3), when the penny is placed at the edge of the record. Ignore the size of the penny. The Attempt at...

Homework Statement A 0.5kg puck on a frozen pond is given an initial speed of 20m/s. If the puck always remains on the ice and slides 115m before coming to rest, determine the coefficient of kinetic friction between the puck and ice. Homework Equations mass= 0.5kg force of gravity= mass...

Homework Statement Prove that the translation friction coefficient for a sphere (protein) with a molecular weight of 25 kiloDaltons is approximately 60% the translation friction coefficient for a 100 kiloDalton protein sphere. Homework Equations Stoke's Law: f = 6πηr where f =...

Homework Statement Hopping into your Porsche, you floor it and accelerate at 11.2 m/s2 without spinning the tires. Determine the minimum coefficient of static friction between the tires and the road needed to make this possible. Homework Equations well I know fs/N= the coefficient...

Homework Statement A force of 105N is applied horizontally to a 20.0 kg box to move it across a horizontal floor. If the box has an acceleration of 3.00 m/s^2, find the coefficient friction.Homework Equations coefficient friction = Ff/FnThe Attempt at a Solution I converted the mass into...

Homework Statement A coin is placed 11.0cm from the axis of a rotating turntable of variable speed. When the speed of the turntable is slowly increased, the coin remains fixed on the turntable until a speed of 36rpm is reached and the coin slides off. What is the coefficient of static...