Force of friction Definition and 140 Threads

If an object on a horizontal platform is moving at a constant velocity of 10m/s, and then begins to accelerate, what happens to the force of friction? Some people are telling me that the force of friction decreases and therefore the object accelerates... HOWEVEr.. force of friction =...

Homework Statement ok, so in need to find the force of friction applied onto a model rocket. I don't want the answer, but how to find thr force of friction Homework Equations i know that Ff=μkFn Fn=mg but i don't know how to find μk

Homework Statement "A 1250 kg slipper hippo slides down a mud covered hill inclined at an angle of 18 degrees to the horizontal. A) If the coefficient of friction is 0.0900, what force of friction impedes the hippo's motion down the hill? B) If the hill were steeper, how would this affect the...

Given a plot of Torque vs Angular acceleration, would it be valid to say that the slope of that line would be the Rotational inertia and the Y intercept to be equal to the force of friction? I think there could be an argument for the Y intercept being the force or TORQUE due to friction. what...

Homework Statement I have a plot whose vertical intercept is 0.00352 [Nm] If the bearings are 2 [mm] from the center of the wheel, then what is the force of friction? Use three significant figures for your answer in Newtons. Homework Equations Torque= (Rotational Inertia)(Angular...

Homework Statement Three blocks are released from rest and accelerated at 1.5 m/s^2. What is the magnitude of the force of friction on the block sliding horizontally? Homework Equations F net = Mass * Acceleration (adding up 3 EQ's and canceling out variables)...

Homework Statement Whether or not the spring is vertical or not, assuming that the spring is ideal, is Fnet always equal to -kx? Is it incorrect to write the sum of the forces of a vertical spring as Fnet = -kx - mg? And does hooke's law account for the force of friction on a horizontal...

I'm a programmer and I've been working on a simulation that involves some physics. Part of my simulation involves two 3D spheres colliding where each sphere has its own mass and velocity. I already found code that handles that and applies conservation of momentum to get the new resulting...

Homework Statement A 25 kg block is pulled up a ramp 20 meters long and 3 meters high by a constant force of 120 N. If the box starts from rest and has a speed of 2 m/s at the top, what is the force of friction between the box and the ramp? Homework Equations The Attempt at a Solution

For the question: A 435 n box is sliding down a 40.00 inclined. If the acceleration of the box is 0.250m/s2. Which formula would I use to find just the force of friction? and would I change the Newtons to kilograms?

Homework Statement A block of wood is pulled by a horizontal string across a rough surface at a constant velocity with a force of 20 N. The coefficient of kinetic friction between the surfaces is 0.3. The force of friction is A) impossible to determine without knowing the mass of the block...

The question is BASICALLY: A ball is rolling on a cement floor (accelerating). Determine the friction force required to stop the ball. Of course it gives you the weight and speed of the ball, and I believe i know the answer. I just want to check it. If I figure out the magnitude of of...

Hey I have to do a project in which I am going to roll a soccer ball across different surfaces such as turf, grass, concrete, etc... and calculate the force of friction of each of these surfaces. I believe that i need to find the Initial force of the ball, then the final and subtract to find the...

Homework Statement I have a lab project in physics and I'm having a bit of trouble. We measured the Applied force of a moving block of wood using a spring scale. The first trials were don't with just the table , knowing the mass and applied force I was able to find the friction force; simply...

Homework Statement Well I am trying to figure out how to find mu if you don't know the force of frictionHomework Equations An example is a 2.25 kg block is accelerating at an acceleration of 5 m/s/s and is on a 40 degree ramp. What is the force of friction and what is mu? The Attempt at a...

Homework Statement A sled is pulled at a constant velocity across a hrizontal snow surface. If a force of 8.0 x 10^1 N is being applied to the sled rope at an angle of 53 degrees to the ground, what is the magnitude of the force of friction of the snow acting on the sled? Homework...

Homework Statement A 15 kg child slides, from rest, down a playground slide tht is 4.0 m long, as shown in the figure. The slide makes a 40 degrees angle with the horizontal. The child's speed at the bottom is 3.2 m/s. What was teh force of friction that the sldie was exerting on the child...

I'm just doing dynamics of rotational motion and was wondering if anyone could help me with the direction the friction points when you have a rope looped around a cylinder and it starts unwinding. The book says the force of friction does no work and is also responsible for the cylinder to...

Homework Statement A 4.0-kg block is lowered down a 37° incline a distance of 5.0 m from point A to point B. A horizontal force (F = 10 N) is applied to the block between A and B as shown in the figure. The kinetic energy of the block at A is 10 J and at B it is 20 J. How much work is done on...

Homework Statement In the figure, a string is used to pull a disk of radius 18 cm and mass 9.3 kg. If the incline is 37° and the tension in the string is 20 Newtons find the acceleration of the disk and the force of friction on it. Homework Equations T=I(alpha) The Attempt at a...

Homework Statement A 12-g coin slides upward on a surface that is inclined at an angle of 12° above the horizontal. The coefficient of kinetic friction between the coin and the surface is 0.23; the coefficient of static friction is 0.35. Find the magnitude and direction of the force of...

Consider the case that when pushing stops the mass stops moving. And that when pushing, it moves with constant speed. For example, one tells you that F=(some material constant)(momentum)mg or something else like that. Actually with some kind of reasoning I get that it should be...

Homework Statement A bowling ball with radius (R) and mass (m)hit the ground and traveled a distance (d) before it started to roll due to the force of friction cause by the coefficient of friction (mu) between the ball and the lane. Homework Equations I=2/5mR^2 F=ma torque=I*alpha...

Homework Statement The front brake pads on your car wear out faster than the rear brake pads; in fact, some cars are specifically designed with large front brake pads because of this. This results from the fact that when a car is braking the magnitude of the friction force acting on the...

Homework Statement A hollow spherical shell with mass 1.50 kg rolls without slipping down a slope that makes an angle of 39.0^\circ with the horizontal. a) Find the magnitude of the acceleration a_cm of the center of mass of the spherical shell. b) Find the magnitude of the frictional...

Homework Statement The diagram shows a 5kg block of lead released from rest at the top of an incline. The block has a speed of 6 m/s when it reaches the bottom. The angle between the slope and the ground is 40° and the slope is 10 m long. a) What is its PE at the top? b) What is...

A force of 1.2N is applied to an object of mass 1.5Kg. It accelerates at 0.50 m/s^2. Determine the Force of friction and the Coefficient of Friction This is what I did. However, it seems that the Force of Friction is really low so I'm not sure if I did this question right. F=M * A ..which is...

Homework Statement A wooden crate with a mass of 20.0 kg is dragged across a floor at a constant speed by a force of 85.0N. The magnitude of the force of friction here is ____ N. Homework Equations The Attempt at a Solution

A wooden crate with a mass of 20.0 kg is dragged across a floor at a constant speed by a force of 85.0N. The magnitude of the force of friction here is ____ N. I'm not even sure how to start.

a horizontal force of 200 Newtons is applied to a 55 kg cart across a 10 meter surface. If the cart accelerates at 2 meters/second squared, then what is the work done by the force of friction as it acts to retard the motion of the cart ?? Work= FX work= maX 55 kg x 2 x 10 = 1100 - 200 N =...

I need help on this problem. I thought I knew how to get it, but this is a multiple choice question, and my result wasn't any of the answers. An 80-kg man is one fourth of the way up a 10-m ladder that is resting against a smooth, frictionless wall. If the ladder has a mass of 20 kg and it...

How to find acceleration. With only Force of friction?? Homework Statement While traveling down between floors at a constant speed, a passenger has a weight of 800 N. During the acceleration to stop the elevator, the passenger experiences an apparent weight of 1000 N. Calculate the...

Homework Statement A 45-kg merry-go-round worker stands on the ride's platform 6.3m from the center. If her speed as she goes around the circle is 4.1 m/s, what is the force of friction necessary to keep her from falling off the platform? Homework Equations f=ma Ac=v^2/r mu=v^2/rg...

HELP finding FORCE OF FRICTION? 1. I'm pulling a 4.24kg block UP a ramp. 2. The normal force is 9.21 N. 3. The "motion" force as it is being pulled up the ramp at constant velocity is 3.5 N. What is the force of friction acting on the block?? Please help...I've pondered over this...

I've been working on a simulation of a Lorenz Waterwheel, and friction was killing it - I couldn't use realistic coefficients of friction. The problem, I discovered was that I was not using the correct equation to calculate the force of friction that counters the wheel's rotation. Having...

Homework Statement Hi everyone, I have 2 quick Questions, about my HW so if u think u can give me a hit please post. Homework Equations the Question was :- 10g bullet is fired into a ballistic pendulum made from a 4kg wood block and two light cords. The block's vertical displeacment...

Homework Statement A window cleaner of mass 95 kg places a 22-kg ladder against a frictionless wall at an angle of 65 degrees with the horizontal. The ladder is 10m long and rests on a wet floor with a coefficient of static friction equal to 0.40. What is the maximum length that the window...

Homework Statement A 230.0 kg bear grasping a vertical tree slides down at constant velocity. What is the friction force between the bear and the tree? Homework Equations The Attempt at a Solution

Homework Statement "A force of 300N is applied to a 70kg carton on a level floor at an angle of 15deg below the horizontal. The coefficient of static friction is 0.4 and the coefficient of kinetic friction is 0.28. Find the friction force acting on the carton." I don't know which...

Homework Statement What is the value of the force of friction? Acceleration = 1m/s^2 Applied force = 5.5N Homework Equations :confused: The Attempt at a Solution :confused: I know what to do if mass or a coefficient of friction were given, but unfortunately they're not...

Homework Statement Suppose a slide similar to Der Stuka is 36.0 meters high, but is a straight slope, inclined at 45° with respect to the horizontal. (a) Find the speed of a 51.1 kg thrill seeker at the bottom of the slide, assuming no friction. 26.5 m/s (b) If the thrill seeker has a speed...

Homework Statement A 60 kg crate is being steadily dragged along the floor by a rope, which makes an angle of 70 degress with the horizontal. If the tension in the rope is 20N: What is the force of friction? What is the coefficient of friction? Homework Equations ffr=Ufn ffr=Umgcos0...

Homework Statement A 3812.0 kg truck is parked on a 18.1° slope. What is the friction force on the truck? Homework Equations The Attempt at a Solution So i set up a triangle with and then used: weight of truck= (9.8 m/s^2 *3812 Kg) = 37367.6 N sin(18.1) = (37367.6 N) /(-Ff) Ff =...

Homework Statement Two blocks, A and B remain stuck together as they are pulled to the right by a force F = 200 N to the horizontal right. B is on a rough horizontal tabletop (coefficiant of kinetic friction is .800) a) what is the acceleraton of the system b) what is the force of friction...

Hey, I am a student in first year of college, going through some of my exam review questions the teacher gave us to polish up on before the exam. would appreciate the help, its probably a really easy question; but I am just getting into physics...went through a bunch of differerent things...

Homework Statement As shown in the figure, a block is pushed up against the wall. Let the mass of the block be m=2.3 kg, the coefficient of kinetic friction between the block and the wall be µ= 0.53, and θ= 62. Suppose F = 68 N. The acceleration of gravity is 9.8 m/s^2. Find the force of...

1. How much frictional force is acting on a 75 kg cart if a push of 220N results in an acceleration of 2.0m/s2? (hint: how much force would have been required to accelerate the cart at that rate if there were no friction - the extra force is the amount needed to overcome friction)...

1. You slide a 326-N trunk up a 20.0° inclined plane with a constant velocity by exerting a force of 211 N parallel to the plane. (a) What is the component of the trunk's weight parallel to the plane? (b) What is the sum of your applied force, friction, and the parallel component of...

A grocery cart is being pushed with a force of 450 N at an angle of 30.0 degrees to the horizontal. If the mass of the groceries is 42 Kg, (a) Calaculate the force of friction if the coefficient is 0.60. Alright guys I have been doing this problem for around two hours. My physics teacher isn't...

Homework Statement A box of textbooks of mass 24.0 Kg rests on a loading ramp that makes an angle θ with the horizontal. The coefficient of kinetic friction is 0.25 and the coefficient of static friction is 0.36. a)As the angle is increased, find the minimum angle at which the box starts...