Coefficient of friction Definition and 411 Threads

Homework Statement A wooden block with mass 0.1305kg is sitting on a horizontal dynamics track. The block is attached to a counterweight of mass 0.050kg by means of a frictionless pulley (the counterweight is hanging off of the table). The system is released from rest, and after traveling...

Hi If i am not wrong than coefficient of friction (mu) is not dependent on the area of the surface of the body in contact with other body. Then why is that rolling friction is less than static friction

Homework Statement A block of wood is sitting on an inclined plane. One end of the plane is rised until the wood block slides down. The wood block slides down when the plane has an angle of 30 degrees to the horizontal. What is the coefficient of friction? Homework Equations uFn=Ff...

Homework Statement Can coefficient of friction between any 2 surfaces be greater than 1 ? If not why ?

I am not a student, but once took physics in college more that 20 years ago. I have the following problem that I am having trouble with: A book has a mass of 400 grams. When you slide the book against the floor with a force of 5 N, it accelerated at a rate of -1.5 m/s^2. What would...

why coefficient of friction is less than 1? dose it have a phisical answer

A hollow, spherical shell with mass 1.95 rolls without slipping down a slope angled at 30.0. Find the minimum coefficient of friction needed to prevent slipping. I have already calculated the acceleration of the sphere and the magnitude of the friction force on the sphere in previous parts...

The question: The driver of a 1.2X10^3 kg car traveling 45 km/h [W] on a slippery road applies the brakes, skidding to a stop in 35 m. Determine the coefficient of friction between the road and the car tires. Equations: - Ff = uFn - d = 0.5 (Vi + Vf) * time - Fn = mg - F = ma...

[b]1. The problem statement An olympic skier moving at 20.0 m/s down a 30.0 degree slope encounters a region of wet snow and slides 145 m before coming to a halt. What is the coefficient of friction between the skis and the snow?[b] [b]2. Homework Equations Mk=Ff/Fn...

Homework Statement 1. A couch with a mass of 1x10^2 kg is placed on an adjustable ramp connected to a truck. As one end of the ramp is raised, the couch begins to move downward. If the couch slides down the ramp with an acceleration of 0.70 m/s^2 when the ramp angle is 25 degrees, what is...

i need help bad. i have a deadline that i need to complete very soon. please if anyone can help. i know i don't have the right answer: a 4.40 kg block is pushed along the ceiling with a constant applied force of 89.0 N that acts at an angle of 66.0 degrees with the horizontal. the block...

[b]1. If a wooden box was pulled up the inclined plane at a constant speed using a spring scale. How would an equation be derived for uk, us, Ff, and N. Homework Equations So to get N. The equation would be N=mg-F (sin (theta)). with F being the reading on the spring scale. Ff would be...

I have this physics lab due on friction. Aim: To determine the value of the coefficient of friction by measuring sliding friction of a block on the table and carrying the normal force. I need a detailed explanation on why the frictional force is increased when the mass is increased. Does...

Hey, I was wondering if someone could help me with this statics problem. The question is: "The 1600kg car is just beginning to negotiate the 16* ramp. If the car has rear-wheel drive, determine the minimum coefficient fo static friction required at B. My FBD: The answer I keep getting...

The question states: "What is the coefficient of friction between a sled and a plane inclined at 30 degrees from the horizontal if the sled just slides without accelerating when given an initial push?" I have drawn a free-body diagram and labeled all of the forces (I think i labeled all of...

hey guys i am really stuck i need to find the derivation for the coefficient of friction between metal and wood, there are no numerical values to calculate i just need to figure out out the heck you derivate this! mu = (1/cos theta)*[(W/mg)- sin theta] It is a system where the wooden...

I am having a lot of trouble with this problem: A car is traveling at 45.0 km/h on a flat highway. If the coefficient of friction between road and tires on a rainy day is 0.100, what is the minimum distance in which the car will stop? I know it uses the delta X kinematics equation, so I...

What are the static and dynamic friction values for dry and wet soap? I can't find these things anywhere on the net, except for an assumption of the kinetic value of 0.06. If someone has access to an extensive data sheet on frictional values, then that would help greatly. Thanx

I just started with my Grade 12 Physics (Univeristy Level), and I would like some help (not necessarily an answer) but an explanation. Here it is: A small box is resting on a larger box, which in turn sits on a table. When a horizontal force is applied to the larger box, both boxes...

Hello, please help me out on this: Two equall masses lie on each side of a rough wedge, connected by a string, the wedge makes anlges 53, and 47, to the horizontal, find the coefficient of friction for the masses to move at a constant speed. MY THINKING: since masses are equal: mgsin(53) =...

A small box resting on a larger box, which in turn sits on a table. When a horizontal force is applied to the larger box, both boxes accelerate together. The small box does not slip on the larger box. If the acceleration of the pair of boxes has a magnitude of 2.5 m/s^2, determine the...

A racing track has a corner which is banked at an angle of 30 degrees cars passing round the corner travel in an acr of a circle of radius 20 metres. car is traveling at 30 m/s and using g as 10 instead of 9.81 I need to find the smallest value of the coeffiecent of friction needed to...

A grindstone in the shape of a solid disk with diameter 0.510 and a mass of m= 50.0kg is rotating at w = 900rev/min. You press an ax against the rim with a normal force of N= 160N, and the grindstone comes to rest in 7.00sec. Find the coefficient of friction between the ax and the...

Block A of mass 2m hangs from a cord that passes over a pulley and is connected to block B of mass 3m. Block B is free to move on a frictionless horizontal surface. The pulley is a disk with frictionless bearings, having radius R and moment of inertia 3MR^2. Block C of mass 4m is on top of block...

You are driving a 2500.0-kg car at a constant speed of 14.0 m/s along an icy, but straight and level road. While approaching a traffic light, it turns red. You slam on the brakes. Your wheels lock, the tires begin skidding, and the car slides to a halt in a distance of 25.0 m. What is the...

how do i find the coefficient of friction of a block? is it Ff/Fn? the problem is how do i find the friction force?

The problem: A 2.00 x 10^3 kg car rounds a circular turn of radius 20.0 m. If the road is flat and the coefficient of static friction between the tires and the road is 0.70, how fast can the car go without skidding? I know that I must use the formula F_c=\frac{mv^2_T}{r} and so I come up with...

I need help on this question, The coefficient of friction between a 4.0 kg box and the floor is 0.60. How large of a horizontal force is necessary to give the box an acceleration of 2.0m/s²?

If the coefficient of static friction between a table and a rope is \mu_{s} , what fraction of the rope can hang over the edge of a table without the rope sliding? Ok, so I declared two variables, P and 1-P . From here, all I know is that mass and weight are not of any concern in this...

Hey everyone, Does anyone know what the kinetic coefficient of friction for pine on pine is? I am looking for the actual value in order to do some percent error calculations. Thanks, ccflyer

traveling at a speed of 58km/h, the driver of an automobile suddenly locks the wheels by slamming on the brakes. the coefficient of friction between the tires and the road is .720 how far does the car skid before coming to a halt? i have absolutely no clue what to do?:confused:

Hello, In class we were given the following task: Analyse the motion of an object rolling down a ramp to determine the coefficient of friction. Use the information obtained and projectile motion analyses to determine the distance a projectile will travel when launched off the end of a...

Okay I'm really stumped on this question and I would be really glad if someone can take me step by step on how to do this question... I have the answer but I have no clue how to obtain it! The Question is: I obtained the answer for the force of friction by just using Fhorizontal = cos55 *...

encountered this problem on a quiz in my physics class. The teacher has one way of doing it, which I believe is wrong. A box sits on an incline plane set at 35 degrees to the horizontal. Find the coefficient of friction if the box is being pulled up the ramp at a constant velocity (net force...

Hi, I'm new to this forum and I hope I can find some help with my AP Physics class! I find the subject really interesting, I just have a hard time applying it. Also, I don't really know the people in my AP Physics class, so it would be awkward to ask them for help. Anyway, last week we did...

I have a box at rest on a plane raised to the critical angle. I need to derive the formula \mu_s=mgtan(\theta) I know f_s/n=\mu n=f_y=mgcos(\theta) f_s=f_x=mgsin(\theta) This leaves me with tan(\theta)=\mu cause the mg cancel out... what did I do wrong?

My question is: If a car is moving at 33m/s^-1 down a 20 degree slope, the friction between car tires and the road surface is 0.58, what is the shortest distance and time in which it can stop? I assume that Fmax= u R is correct formula? (where Fmax=force max, u=coeff of friction, and R=...

hi, I am doing a physics project in which I am building a hovercraft. i want to show mathematically how the craft lowers the friction, however, i cannot find the coefficent of friction for air. i found the coefficient of friction for concret on rubber to be roughly 0.8... any ideas on air...

Hi all! How do you calculate the coefficient of friction for a tyre sample going against concrete? My experiment involves a uniform piece of concrete angled at 30 degrees with a pulley attached at the raised end. The tyre sample is placed at the end of the concrete slab and is loaded...

ok i worked out the problem but i got the wrong answer. the values i got are: for normal force=69.62N. for ap=12.19. for af=6.19. for Ff=24.8N final answer=.356 and i need .816 what did i do wrong? here is the problem again: A 4kg block is pushed alomng the ceiling with a constant apllied...

A 198g wood block is firmly attached to a very light horizontal spring, as shown in the figure below. The block can slide along a table where the coefficient of friction is 0.287. A force of 23.1 N compresses the spring 17.7 cm. If the spring is released from this position, how far...

What is the relationship between static, kinetic, and rolling? Is static supposed to be less than kinetic and kinetic less than rolling? Can someone help me out?

Help me! (mu K) Will someone PLEASE explain to me how to find the coefficient of friction when given the following: a box weighing 325 N moving with constant velocity across a floor, and it is being pushed with a force of 425 N exerted downward at an angle of 35.2 degrees below horizontal...

A 2 kg metal plate slides down a 10m high slope. If the slope is 49 degrees, and the speed at the bottom is 8m/s what is the coefficient of friction? This is what I tried: Wf = F x d I found the work done by Eg = Ek+Wf and then found d with 10/cos49... then I tried M = Ff/Fn (Fn found by...

A 52-N sled is pulled across a cement sidewalk at a constant speed. A horizontal force of 36 N is exerted. What is the coefficient of sliding friction between the sidewalk and the metal runners of the sled? What formulas would I use in this problem?

I got a problem: let's say a car traveling around a circular race track of radius 340m. The lateral acceleration of the car is 1.2g. The roadway of the track is level, not banked. What is the mininum speed at which the car can travel on the track without rolling over? What is the minimum...

Hello, I'm stumped about a relatively simple problem. Here it is in its exact form: "You need a rectangular prism with its height at least several times greater than its length. Put this prism vertically on a table or any other horizontal plane. How does one determine the coefficient of...

physics help! :confused: Ok, I have understood every problem we have done so far except this one, You are wearing shoes that have a coefficient of friction on rock of 0.70. On how steep a rock slope could you stand without slipping? So far i have gotten: Fs=Fparallel= mu*W*costheta...

Hi I'm new here, I hope someone can help me. I think I got the first half of the question, but I got stuck one the second part. Well here it goes, A force of 40N accelerates a 5.0kg block at 6.0m^2 along a horizontal surface. a.) How large is the friction force? b.) What is the...

If the coefficient of friction is derived by f=un... and u can be calculated as u=sinx/cosx or tanx; Then why is there still friction on a level surface where x=0 and tanx also equals 0? Im a beginner in physics. i just need help understanding :frown: