Kinetic friction Definition and 509 Threads

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...

Homework Statement Two blocks with masses 4.00 kg and 8.00 kg are connected by a string and slide down a 30.0 degree inclined plane. The coefficient of kinetic friction between the 4.00 kg and plane is .25; that between the 8.00 kg block and the plane is .35. a) Calculate the acceleration...

Homework Statement A 40.0kg box initially at rest is pushed 5.00 m along a rough, horizontal floor with a constant applied horizontal force of 130 N. The coefficient of friction between box and floor is .300. Find the change in kinetic energy of the box. Homework Equations...

Homework Statement A sled weighing 210 N rests on a 15° incline, held in place by static friction. The coefficient of static friction is 0.50. (c) The sled is now pulled up the incline at constant speed by a child. The child weighs 546 N and pulls on the rope with a constant force of 100...

1. Why does a crate on an accelerating truck accelerate backwards proportional to the amount of kinetic friction? I don't understand why the crate accelerates backwards as if kinetic friction was the only force acting on it. 2. Homework Equations : F=ma

Homework Statement An 81-kg baseball player slides into second base. The coefficient of kinetic friction between the player and the ground is 0.49. (a) What is the magnitude of the frictional force? (b) If the player comes to rest after 1.6 s, what was his initial velocity? Homework...

A 9.00 kg hanging weight is connected by a string over a light pulley to a 5.00 kg block that is sliding on a flat table (Fig. P5.8). If the coefficient of kinetic friction is 0.560, find the tension in the string. fk = µkN, F = ma, N2 = m2g, 5.00 kg mass = m2, 9.00 kg mass = m1 N =...

Homework Statement Run a trial with an angle of 28 degrees so the block is in translation equilibrium. Show how to calculate the mu_k value. http://www.lon-capa.org/~mmp/applist/si/plane.htm Homework Equations F_fk = mu_k * F_n The Attempt at a Solution I have solved for Normal...

My physics prof's father died last week, and rather than cancel class, a different prof taught our class (by different, I mean a different one each day). This assignment was emailed to us by the head of the physics department, who spent less than five minutes with the class, and did not explain...

I have a question that I am having trouble with hopefully someone can help me. Here it is Static and Kinetic Friction: A 10 kg crate is at rest on a horizontal table (s =0.8, k =0.3). Then various amounts of horizontal pushing force are applied to it. a.) The largest pushing force that can...

Homework Statement "A bread truck is traveling at 18 m/s on a horizontal road. The brakes are applied and the truck skids to a stop in 3.6s. The coefficient of kinetic friction between the tires and the road is:" Homework Equations Kinetic Friction = coefficient of kinetic friction x...

Homework Statement "A forward horizontal force of 50N is used to pull a crate, which weighs 250N, at a constant velocity across a horizontal floor. The coefficient of kinetic friction is:" Homework Equations Frictional force = coefficient of kinetic friction x normal force The Attempt...

A 1000-N crate is being pushed across a level floor at a constant speed by a force of 300 N at an angle of 20.0 degrees below the horizontal. a) What is the coefficient of kinetic friction between the crate and the floor? b) If the 300 N force is instead pulling the block at an angle of 20.0...

Homework Statement On a level road with its brakes on, a car traveling at 86 km/hr stops within 93 m when the brakes lock and the car slides. - a) What is the magnitude of the acceleration of the car? 3.0967 which i already found. - b) What is the coefficient of kinetic friction between...

Homework Statement blocks 1 and 2 of masses m1 and m2 respectively, are connected by a light string. these blocks are further connected to a block of mass M by another light string that passes over a pulley of negligible mass and friction. blocks 1 and 2 move with constant velocity v down...

how do i find it if i am given 20kg sled being pulled with a force of 80N at 30 degrees above the horizontal

hello everbody...i got two question about kinetic friction force... tat is 1. is kinetic friction force of an object always the same value?as the formula kinetic friction force = coefficient of kinetic friction force*normal , coefficient of kinetic friction force is always the same...is me...

Tension / Kinetic Friction Help! Please help me.. i can't figure out how to solve this problems.. * A taboggan slides down a hill and has a constant velocity. The angle of the hill is 8.00 degrees with respect to the horizontal. What is the coefficient of kinetic friction between the surface...

Homework Statement A horizontal force of 150 N is used to push a 40.0 kg packing crate a distance of 6.00 m on a rough horizontal surface. If the crate moves at constant speed, find the coefficient of kinetic friction between the crate and the surface. Homework Equations fK= coeff. of...

I don't know if you guys have heard that, when a railroad car is about to start moving, railroad operators sometimes have the train go backwards a little bit at first, that way when they move forward the force of the engine car only has to overcome the Static friction of one cart at a time, as...

Homework Statement Ugonna stands at the top of an incline and pushes a 100 kg crate to get it started sliding down the incline. The crate slows to a halt after traveling 1.5m along the incline. The initial speed is 2.0 m/s and the angle of incline is 30 degrees. What is the coefficient of...

Homework Statement A student is pushing horizontally on a table (m=16 kg) to move it across a horizontal floor. The coefficient of kinetic friction between the table and the floor is 0.61. a) Determine the magnitude of the applied force needed to keep the table moving at constant velocity...

Homework Statement A child slides down a slide with a 28 degree incline, and at the bottom her speed is precisely half of what it would had been if the slide had been frictionless. Calculate the coefficint of kinetic friction between the slide and the child. Homework Equations N=...

Homework Statement I am having trouble with a problem from Physics for Scientists and Engineers by Tipler and Mosca, 6th edition, 5.56 A 100-kg mass is pulled along a frictionless surface by a horizontal force F such that its acceleration is a1=6.00m/s^2. A 20.0-kg mass slides along the top...

[SOLVED] Calculating coefficient of kinetic friction Homework Statement An applied force of 450 N {forward} is needed to drag a 1000-kg crate at constant speed across a horizontal, rough floor. Calculate the coefficient of kinetic friction for the crate on the floor. Fapp=450 N {forward}...

Homework Statement To calculate the kinetic friction of a block of wood and determine its acceleration by timing it as it travels down a slope. The equipment available consists: of a plank of wood, clamps etc. for raising one end of it to give an inclined plane, blocks to slide down the...

Homework Statement A 425 g block is at rest on a horizontal surface. The coefficient of static friction between the block and the surface is .770, and the coefficient of kinetic friction is .220. A force of magnitude P pushes the block forward and downward. Assume the force is aplied at an...

I am trying to create a 3d physics simulation and the first "problem" I have encountered is implementing realistic friction. Now, I was told by some professor that the faster an object is traveling the less friction that it has, however, I have not been able to find the appropriate equation/s on...

Is a difference in .07 when it comes to coefficients of kinetic friction for the same object on the same surface significant? I thought it was, but I have yet to determine a reason why. Below is an explanation of my experiment, as brief as possible...

Springs, Kinetic Friction, and Distance...help me please 1. In the figure below a 1.4 {\rm kg} block is held at rest against a spring with a force constant k = 740 {\rm N/m}. Initially, the spring is compressed a distance d. When the block is released, it slides across a surface that is...

Homework Statement In the figure below, a box of ant aunts (total mass m1 = 1.15 kg) and a box of ant uncles (total mass m2 = 3.60 kg) slide down an inclined plane while attached by a massless rod parallel to the plane. The angle of incline is θ = 30°. The coefficient of kinetic friction...

[SOLVED] Tension with horizontal kinetic friction Homework Statement In Figure, block 1 of mass m1 = 1.8 kg and block 2 of mass m2 = 1.3 kg are connected by a string of negligible mass. Block 2 is pushed by force of magnitude 20 N and angle θ = 39°. The coefficient of kinetic friction between...

[SOLVED] Mass of a block via kinetic friction Homework Statement In Fig, two blocks are connected over a pulley. The mass of block A is 5.9 kg and the coefficient of kinetic friction between A and the incline is 0.36. Angle θ of the incline is 43°. Block A slides down the incline at...

The drawing shows a 28.8-kg crate that is initially at rest. Note that the view is one looking down on the top of the crate. Two forces, F1 and F2, are applied to the crate, and it begins to move. The coefficient of kinetic friction between the crate and the floor is k = 0.374. Determine the (a)...

Homework Statement Physics problem - coefficient of friction? Bonnie and Clyde are sliding a 300 kg bank safe across the floor to their getaway car. The safe slides with a constant speed if Clyde pushes from behind with 385 N of force while Bonnie pulls foward on a rope with 350N of force. What...

If I am running in a straight line, and I am experiencing kinetic friction that is proportional to my weight, i.e. my normal force, then when I run around a curve, does my normal force increase by my velocity squared divided by the radius of the turn as if it were a perfect circle (...

Homework Statement You use 30N (**Not 25 N, that was a typo) to slide a wooden box that is 12 kg across a floor at constant velocity. What is the coefficient of kinetic fricition? Homework Equations Ff=coeff of kinetic friction (mu k) m*g ?? not sure. The Attempt at a Solution...

I need some serious help with my homework. I have no idea how to solve the following problem: A 925 N crate is being pushed across a level floor by a force F of 325 N at and angle of 25 degrees above the horizontal. The coefficient of kinetic friction between the crate and floor is 0.25...

Homework Statement A baseball player slides into third base with an initial speed of 7.90 m/s. If the coefficient of kinetic friction between the player and the ground is .41, how far does the player slide before coming to rest? Homework Equations The Attempt at a Solution I...

I was hoping somebody could check over my work and see if I have the correct answer for this problem, as my text hasn't been the greatest in explaining this. QUESTION A sight seen on many bunny hills across Ontario is young skiers pushing on ski poles and gliding down a slope until they come...

Homework Statement A father pushes horizontally on his daughter's sled to move it up a snowy incline, as illustrated in the figure, with h = 3.9 m and = 11°. The total mass of the sled and the girl is 35 kg and the coefficient of kinetic friction between the sled runners and the snow is...

A 115.0 kg box slides down a 25.0 degree ramp with an acceleration of 2.60 m/s squared. Find the normal force, the net force down the ramp, and the force of kinetic friction. Gravity = 9.81 m/s2 Force of gravity = ma Mew k = Force of Kinetic Friction/Normal Force These are the parts that I've...

Mk Homework Statement The coefficient of kinetic friction of a block depends on: A. normal force. B. surface area of the 2 materials c. mass of block d. speed of block e. what the 2 materials are made of Homework Equations The Attempt at a Solution SInce friction of a block...

Homework Statement Sam, whose mass is 75 kg, takes off across level snow on his jet-powered skis. The skis have a thrust of 200N and a coefficient of kinetic friction on snow of 0.10. Unfortunately, the skis run out of fuel after only 10 s. a. What is Sam’s top speed...

Homework Statement Just wondering.. does the coefficient of kinetic friction and force of kinetic friction vary with mass? Homework Equations ∑F = mg – Fk = (M + m)a Fk = ukN N = mg uk = [mg – (M + m)a]/Mg The Attempt at a Solution I think that as the mass of an object...

A 37 kg box slides down a 35 degree ramp with an acceleration of 1.35 m/s^2. The acceleration of gravity is 9.81 m/s^2. Find the coefficient of kinetic friction between the box and the ramp. Ff= MkFn 37 * 1.35 = 49.95 N Fgx = 49.95 sin 35 = 28.650143 Fgy = 49.95 cos 32 =...

Here is the problem: A 12.5 Kg wooden crate with an initial velocity of 2.5m/s slides across a rough cement floor for 1.7 m before coming to rest. Find the coefficient of kinetic friction. (Use GUESS method.) The answer is 0.19. The equation you use is: coefficient = kinetic friction/normal...

Homework Statement Sam, whose mass is 75 kg , takes off down a 50 m high, 10 degree slope on his jet-powered skis. The skis have a thrust of 200N . Sam's speed at the bottom is 40 m/s . What is the coefficient of kinetic friction of his skis on snow? Homework Equations Fk = uk N u...