Kinetic friction Definition and 504 Threads

Homework Statement The coefficient of kinetic friction between the two blocks is 0.30. The surface of the table and pulleys are frictionless. m1=2 kg m2=3 kg m3=10 kg Homework Equations \SigmaF=ma T2-m3g=m3a T1-T2=m2a friction-T1=m1a The Attempt at a Solution T2=m3g+m3a...

You and your friend Peter are putting new shingles on a roof pitched at 24^\circ . You're sitting on the very top of the roof when Peter, who is at the edge of the roof directly below you, 5.4 m away, asks you for the box of nails. Rather than carry the 2.4 kg box of nails down to Peter, you...

Problem 1: You need to move a 125-kg piece of furniture in your living room. You and your friend exert a force of 305 N to start it moving. What is the coefficient of static friction between the furniture and the floor? Problem 2: A 20-kg bowling ball slides half way down a lane with a...

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...

1. If the acceleration of a pair of boxes has a magnitude of 2.5m/s^2, determine the smallest coefficient of friction between the boxes that will prevent slippage. Homework Equations F = ma Fk = ukFn Fw = mg The Attempt at a Solution ma = uk mg(Fn) a = uk g a/g = uk...

Homework Statement A 5.20 kg block is set into motion up an inclined plane with an initial speed of v0 = 7.70 m/s. The block comes to rest after traveling 3.00 m along the plane, which is inclined at an angle of 30.0° to the horizontal. (a) For this motion, determine the change in the...

Homework Statement A 880 N crate is being pulled across a level floor by a force F of 395 N at an angle of 25° above the horizontal. The coefficient of kinetic friction between the crate and the floor is 0.25. Find the magnitude of the acceleration of the crate. Homework Equations not...

a dockworker loading crates on a ship finds that a 20kg. crate, intially at rest on a horizontal surface, requires a 75-N horizontal force to set it in motion. However, after the crate is in motion, a horizontal force of 60-N is required to keep it moving with a constant speed. Find the...

Homework Statement In the figure below, the coefficient of kinetic friction between the block and inclined plane is 0.17 and angle θ = 55°. What is the block's acceleration (magnitude and direction) assuming the following conditions? (b) It has been given an upward shove and is still sliding...

Homework Statement A force of 85N is applied to a block on an incline that makes an angle of 35 degrees with the horizontal. The coefficient of kinetic friction between the block and the incline is \muk=0.45. The block is moving and accelerating up the incline at 1.5 m/s2. Homework...

Homework Statement Using Newton's Laws, show how you would measure mu k for an accelerating block. Homework Equations Fnet = ma The Attempt at a Solution I can't seem to relate Fnet to Mu k...

Homework Statement A slide-loving pig slides down a certain 35 degree slide in twice the time it would take to slide down a frictionless 35 degree slide. What is the coefficient of kinetic friction between the pig and the slide? Homework Equations fs = Mk * Fn The Attempt at a...

Homework Statement Bobsled A bobsled run leads down a hill as sketched in the figure above. Between points A and D, friction is negligible. Between points D and E at the end of the run, the coefficient of kinetic friction is µk = 0.4. The mass of the bobsled with drivers is 210 kg and it...

Homework Statement A 2.00 kg steel block is at rest on a steel table. A horizontal string pulls on the block. The coefficient of kinetic friction of dry steel on steel is μk=.600 If the string tension is 16.0 N, what is the block's speed after moving 1.30 m? Homework Equations...

Equation for solving the coefficient of Kinetic friction HELP?? Problem: A cable attached to a block of mass 9 kg pulls the block along a horizontal floor at a constant velocity. If the tension in the cable is 5.2 N, what is the coefficient of kinetic friction between the block and the floor...

Homework Statement You and your friend Peter are putting new shingles on a roof pitched at 20degrees . You're sitting on the very top of the roof when Peter, who is at the edge of the roof directly below you, 5.4 m away, asks you for the box of nails. Rather than carry the 2.1 kg box of nails...

Homework Statement A catcher “gives” with a baseball when catch- ing it. If the baseball exerts a force of 466 N on the glove such that the glove is displaced 11.6 cm, how much work is done by the ball? Answer in units of J. (I got this answer and it is 54.056) Find the coefficient of...

Homework Statement The coefficient of static friction between a block and a horizontal floor is 0.414, while the coefficient of kinetic friction is 0.138. The mass of the block is 5.24 kg. A horizontal force is applied to the block and slowly increased. What is the value of the applied...

Homework Statement If you exert 28N of horizontal force while pushing a 10.2 kg box across the surface of a floor at constant velocity, then what is the kinetic friction coefficient between floor and the box? Homework Equations EF = ma Ffk = uK * Fn The Attempt at a Solution...

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 A 3.00 kg block starts from rest and moves down a ramp on an incline of 30 degrees. If it makes it 2.00 m down the incline in 1.20 s, then: a) what is the acceleration of the block? This answer I got using dX=Vot + 1/2at^2. The answer is 1.78 m/s^2. b) the...

Homework Statement An 85-N box of oranges is being pushed across a horizontal floor. As it moves, it is slowing at a constant rate of 0.90 m/s each second. The push force has a horizontal component of 20 N and a vertical component of 25 N downward. Homework Equations Calculate the...

My problem is with this lab on friction...it is a virtual lab, as I attend a virtual high school. I've put in numerous hours and can't seem to figure out what is wrong. You see, we need to determine max static friction and kinetic friction using this program. For all the objects EXCEPT the dog...

A box of books weighing 325N moves with a constant velocity across the floor when it is pushed with a force with 425N exerted downward at an angle of 35.2o below the horizontal. Find uk between the box and the floor. Please help me I have a test soon and I'm not exactly understanding how to...

You push a 2.5 kg block against a horizontal spring, compressing the spring by 18 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 90 cm from where you released it. The spring constant is 200 N/m. What is the block-table coefficient of kinetic friction...

Homework Statement A box slides down a 30.0 degree ramp with an acceleration of 1.20 m/s^2. Determine the coefficient of kinetic friction between the box and the ramp. Homework Equations μk=f sub k/Fn The Attempt at a Solution With the information I have, I have no samples in my...

A potter's wheel is 101 kg and has radius of 0.483 meters and is freely rotating at 71.9 rev/min. the potter can stop the wheel in 6.54 s by pressing against the rim and exerting a radially inward force of 103 N. find coefficient of kinetic friction. I found alpha=71.9 x 2 x pi/60sec/ 6.54=...

My teacher gave us a homework. We must count the coefficient of kinetic friction between the object and the surface. We can only use the object, ruler and book or table etc. as the surface of motion. We are not allowed to count the acceleration with clock. I decided to make the object slide...

Homework Statement Block A has a mass of 5.56 kg and is on a rough incline of 21.5 degrees to the horizontal. Block B has a mass of 4.66 kg and the coefficient of kinetic friction between Block A and the plane is 0.276. What is the acceleration of the blocks? Homework Equations I used a =...

A sled weighing 100 N is pulled horizontally across snow so that the coefficient of kinetic friction between sled and snow is .275. A penguin weighing 50 N rides on the sled to start with the penguin digs in his claws so he is firmly attached to the sled. What value of F do you need for the...

Hi there, I need help with understanding this guy's solution thanks! The kinetic friction force will be up the slide to oppose the motion. We choose the positive direction in the direction of the acceleration. From the force diagram for the child, we have ?F = ma: x-component: mg sin...

I have no idea of how to start solving this problem. A 5kg box slides 3m across the floor before coming to rest. What is the coefficient of kinetic friction between the floor and the box if the box had an initial speed of 3m/s? Can somebody please help me solve the problem?

Homework Statement You are pulling a child up hill on a sled, walking at a constant v. The incline makes the angle theta with the horizontal, and the rope is parallel to the incline. The mass of the sled plus the child is M, and you pull with a constant force T. Start with making a sketch of...

Homework Statement You and your friend Peter are putting new shingles on a roof pitched at 21^\circ . You're sitting on the very top of the roof when Peter, who is at the edge of the roof directly below you, 5.4 m away, asks you for the box of nails. Rather than carry the 2.4 kg box of nails...

A Physics 1AL student uses a force P of magnitude 80 N and angle θ = 70 (with respect to the horizontal) to push a 5.0 kg block across the ceiling of her room. The coefficient of kinetic friction between the block and the ceiling is 0.40. a) Draw a free body diagram of the system. b) What...

Homework Statement A 2.55 kg block is pushed 1.54 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of 69.9 degrees with the horizontal. The acceleration of gravity is 9.8 m/s^2. If the coefficient of kinetic friction between the block and wall is...

This problem has been giving me some trouble, and I was wondering if anyone could help? A 0.700 kg wood block is firmly attached to a very light horizontal spring (k = 200 N/m) as shown in the figure (Intro 1 figure) . This block-spring system, when compressed 4.7 cm and released, stretches...

Homework Statement I have a system that looks like this: http://dept.physics.upenn.edu/courses/gladney/phys1/homework/images/half_Atwood.gif m2 mass is 0.07kg. The m1 mass is gradually increased. Basically, if you tap it, m2 starts moving by itself at constant speed when m1 is at 0.03kg...

In a truck loading station at a post office, a small 2.00-kg package is released from rest at point A on a track that is one-quarter of a circle with radius 1.60 m. The size of the package is much less than 1.60 m, so the package can be treated as a particle. It slides down the track and reaches...

Homework Statement A box is given a push so that it slides across the floor. How far will it go, given that the coefficient of kinetic friction is 0.25 and the push imparts an initial speed of 3.7 m/s? Homework Equations E is sigma EFy/m = ay -> Fn - mg = 0 -> because ay = 0 -> Fn =...

Homework Statement You have been called to testify as an expert witness in a trial involving an automobile accident. The speed limit on the highway where the accident occurred was 40 mph. The driver of the car slammed on his brakes, locking his wheels, and left skid marks as the car skidded to...

Homework Statement A 1.20 x 102 kg crate is being pushed across a horizontal floor by a force P that makes an angle of 30.0° below the horizontal. The coefficient of kinetic friction is 0.450. What should be the magnitude of P, so that the net work done by it and the kinetic frictional force...

1. Homework Statement Block A, on a horizontal table, has a weight of 4.91N is attached to a rope, that goes over a pulley, attached to Block B, that has a weight of 2.94N. Once block B is set into downward motion, it descends at a constant speed. Assume that the mass and friction of the...

1. A crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of kinetic friction is 0.40. To start the crate moving with the least possible applied force, in what direction should the force be applied? a. Horizontal b. 24 degrees below horizontal c. 22...

Coeffiecient of Kinetic Friction problem? (Shuffleboard and Distance traveled) Homework Statement A shuffleboard disk is accelerated to a speed of 5.8m/s and released. If the coefficient of kinetic friction between the disk and the concrete court is 0.31, how far does the disk go before it...

Homework Statement A firefighter whose weight is 812 N is sliding down a vertical pole, her speed increasing at the rate of 1.45 m/s2. Gravity and friction are the two significant forces acting on her. What is the magnitude of the frictional force? Homework Equations Fk = ukFn uk =...

Homework Statement A 50 kg block slides down a 32° ramp with an acceleration of 3.2 m/s2. What is the coefficient of kinetic friction between the block and the ramp? Homework Equations [SIZE="5"]\mukinetic=\frac{f_{kinetic}}{F_{normal}} The Attempt at a Solution I have gone...

Homework Statement Starting from rest, a 10.6 kg block slides 3.20 m down to the bottom of a frictionless ramp inclined 30.0° from the floor. The block then slides an additional 4.50 m along the floor before coming to a stop. (a) Determine the speed of the block at the bottom of the ramp...

Homework Statement http://nplq1.phyast.pitt.edu/res/msu/physicslib/msuphysicslib/13_EnergyConservation/graphics/prob27a_MechEnWFriction.gif When mass M is at the position shown, it is sliding down the inclined part of a slide at a speed of 2.07 m/s. The mass stops a distance S2 = 1.9 m...

Homework Statement You have been called to testify as an expert witness in a trial involving an automobile accident. The speed limit on the highway where the accident occurred was 40 mph. The driver of the car slammed on his brakes, locking his wheels, and left skid marks as the car skidded to...