What is Rolling friction: Definition and 59 Discussions
Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement) of the wheel, roadbed, etc., is recovered when the pressure is removed. Two forms of this are hysteresis losses (see below), and permanent (plastic) deformation of the object or the surface (e.g. soil). Note that the slippage between the wheel and the surface also results in energy dissipation. Although some researchers have included this term in rolling resistance, some suggest that this dissipation term should be treated separately from rolling resistance because it is due to the applied torque to the wheel and the resultant slip between the wheel and ground, which is called slip loss or slip resistance. In addition, only the so-called slip resistance involves friction, therefore the name "rolling friction" is to an extent a misnomer.
In analogy with sliding friction, rolling resistance is often expressed as a coefficient times the normal force. This coefficient of rolling resistance is generally much smaller than the coefficient of sliding friction.Any coasting wheeled vehicle will gradually slow down due to rolling resistance including that of the bearings, but a train car with steel wheels running on steel rails will roll farther than a bus of the same mass with rubber tires running on tarmac. Factors that contribute to rolling resistance are the (amount of) deformation of the wheels, the deformation of the roadbed surface, and movement below the surface. Additional contributing factors include wheel diameter, load on wheel, surface adhesion, sliding, and relative micro-sliding between the surfaces of contact. The losses due to hysteresis also depend strongly on the material properties of the wheel or tire and the surface. For example, a rubber tire will have higher rolling resistance on a paved road than a steel railroad wheel on a steel rail. Also, sand on the ground will give more rolling resistance than concrete. Sole rolling resistance factor is not dependent on speed.
In pure rolling the of the sphere contact points of the sphere are at zero velocity,how is friction opposite to the motion of sphere being applied to these points?how the frictional force f is bieng applied to the sphere?
I was looking for a way to calculate the friction arising from the axle and wheel of a standard lab cart. I came across this research paper: https://www.usna.edu/Users/physics/mungan/_files/documents/Publications/PhysEd4.pdf
That derived the following equation for the coefficient of rolling...
This image represents the ramp.
The first part is pretty easy.
The red part has friction, and the ball rolls down it. The blue part has no friction, and the ball climbs it only owing to the translational kinetic energy that it gained at the bottom of the red ramp, which is only a fraction of...
Hello,
Static friction implies no relative (maybe just instantaneously) motion between the two objects that are in contact. Rolling friction pertains to rolling objects and develops due to the asymmetric deformation of the surface over which the body rolls (if the deformation was symmetric, the...
Homework Statement
We have a ball of mass ##m##and radius ##r##. it is placed on an incline (We don't know the angle of the incline, nor we do whether the angle is constant along the incline - maybe it is a curved incline) and then released. The COM of ball is ##h## meters above the incline at...
I have conducted an experiment that measures the velocity of an object that is moving on a flat surface. The object rolls on four fixed caster wheels. The wheels are made of some kind of rigid material. Maybe nylon, maybe hard rubber. The total mass of the object, including the wheels, is...
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Hello,
I'm attempting an experiment where I take a cart and slide it down a ramp. Each time, I will coat the ramp with a different liquid. I want to compare the effects of the dry ramp, a ramp with water poured...
Ok...Suppose I try to roll a ball to the right...Its surface at the point of contact with the floor would be deformed, which would cause some ''rolling friction'' to the left, which in turn would cause some clockwise torque(rolling motion) in the ball...(please point out if something is wrong in...
Homework Statement
A cart with mass M has four wheels (idealized as uniform discs), each of radius r and mass m, arranged symmetrically with respect to the cart. Find the acceleration of the cart when a horizontal force F is applied on it. There is no slipping between the wheels and the...
Suppose a cylindrical rod is given a push such that it rolls without slipping on a horizontal plane. Am I right to say that rolling friction is only required at the start when the push is applied to initiate the rolling motion? Once the push is removed, the only forces acting on the rod are its...
Why is there no virtual work done by a rolling friction?
In pure rolling, is the virtual displacement parallel or perpendicular to the surface? I believe it can't be perpendicular because the object is not allowed to lose contact with the surface. But if it's parallel, then there must be a...
I'm not sure whether I understood rolling friction properly. First, I'll assume that both surface and the body are completely rigid (no deformations of body nor surface will happen, thus vector N won't be dislocated creating an opposite momentum). So, rolling friction (assuming there is friction...
" At every instant ,there is just one point of contact between the body and the plane and this point has no relative motion, hence ideally the friction should be zero" --from my textbook
Firstly, I don't understand the "relative motion" part. Can someone please explain.
And we do know in fact...
1) Are there any ways to control the impulse in an collision in a lab condition? I.e. if I set an object connected to a spring and try to hit a ball using the object, are there any ways to control the impulse of the collision?
2) How to detect the change from slipping to pure rolling...
Hi!
My question considers no specific problem, but rather different concepts I have trouble getting my head around. So I would be really happy if you could help me understand different kinds of friction, and maybe above all their direction, acting on a rolling object. :)
Fist we have kinetic...
Homework Statement
A forward force on the axle accelerates a rolling wheel on a horizontal surface. If the wheel
does not slide the frictional force of the surface on the wheel is:
A. zero
B. in the forward direction
C. in the backward direction
D. in the upward direction
E. in the downward...
Hello, members
Why rolling friction is extremely small than sliding friction?
Could somebody explain this to me by an example?
Your help would be appreciated.
Thanks a lot.
You have to apply a force to counter the force of friction. In order to move fast the friction has to be reduced. So we have the invention of wheels. Rolling friction is much less than sliding friction. Experience shows that much less force is required to roll an object than to slide or drag it...
Homework Statement
Two bicycle tires are set rolling with the same initial speed of 3.30m/s along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 psi and goes a distance of 17.3m ; the other is at 105...
I have a concept about rolling friction which someone might be able to confirm for me. Let's say there is a steel ball rolling on a steel surface. It seems to me that the rolling friction force would be proportional to the rolling object's velocity.
My understanding is rolling friction is...
Homework Statement
Two bicycle tires are set rolling with the same initial speed of 3.60m/s along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 psi and goes a distance of 18.0m ; the other is at...
Is rolling friction considered static friction?
After all, the two surfaces are not moving at the point of contact.
My textbook separates static and kinetic friction.
Hello Forum,
Consider a rigid disk that is rotating on a surface. If the surface is elastic but not symmetric, the rotating disk will eventually slow down.
If the surface was perfectly and symmetrically elastic the object will continue to rotate (the front deformation of the surface would...
hey i had a bizarre thought, what if there is a road made with a very smooth friction less surface and a normal asphalt road, arranged alternatively, such that , half the time spend by the tire in one rotation is placed on the smooth side and the other half on the rough side, such that the tire...
Hi there! First off, I am new to these forums so be nice! The question I have isn't homework, but rather personal curiosity.
Homework Statement
Imagine that you have some type of cart on a conveyer belt. The cart is held stationary with respect to the world by a rope. The conveyer belt...
When looking at rolling objects, the force of rolling resistance is determined by a coefficient of rolling friction. Is this coefficient constant for an object when both stationary and moving? Or is there a separate static and kinetic coefficient as there is with sliding friction?
I am asking...
problem 1:
Homework Statement
this isn't quite a problem but a general confusion about how to setup the problem. for example:
a cylinder of radius R with mass M has a force T applied at its center of mass, pointing horizontally to the right. assuming the cylinder only rolls without...
Hi there. The thing is that in my laboratory project me and my companion tried to determine the rolling coefficient resistance for a steel ball rolling over an inclined plane of aluminium. Everything is fine till there, I've donde almost all the work. The thing is that I wanted to reference...
Does friction does any work on an object purely rolling? Would mechanical energy be always conserved when when an object rolls?
I feel that friction does no work as the point of contact never moves. So there will be no change in energy.
Am I having conceptual error?
Hello,
I need to apply rolling friction to a ball, but I don't understand where to plug it in.
I know the rolling friction that I want to put in, but I can't just subtract the force of rolling friction on velocity, because the ball would never come to a stop, it would turn back again (and make...
Homework Statement
What is the value of the rolling friction force given 1)Fnet=0.24N (deceleration up the ramp) and 2)Fnet=0.21N (acceleration down the ramp)?
Homework Equations
Fnet = Fgravity - Ffriction (?)
The Attempt at a Solution
Somehow I need to combine these values to...
Alright, everyone, I have some questions in regards friction when rounding a flat curve and was hoping to get some help with it. For that intent, I've borrowed a couple of posts from another old thread on the topic of centripetal force. Hope the authors don't mind.
The textbook I'm using...
help please I don't know what to do with this problem can someone please tell me how to solve the following problems, i need to know how to solve and get the right answers not just get the right answers.
A force of 1000N is applied to a 1200kg car if the coefficient of the rolling friction is...
Homework Statement
A disk of mass 6 kg and outer radius 60 cm with a radial mass distribution (which may not be uniform) so that its moment of inertia is \large_{{\frac{2}_{7}}mR^2}. The disk is rotating at angular speed 7 rad/s around its axis when it touches the surface, as shown. The disk...
[Urgent] Rolling Friction
Homework Statement
How would you calculate a rollin friction? I have a toy car and it is going down the ramp that is 12 degrees above the horizontal.
im very new with this.
the car's Radius is 0.3cm.
what experiment would i have to find this out? please i...
Homework Statement
I preformed a experiment to find the joules of work taken for my elastic band car to travel a distance of 18.1 meters
Does my result seem correct?
When an object is said to be under pure rolling, what friction does it experience? Static, kinetic or rolling friction?
If its not rolling but rather just rotating and translating, what friction does it experience?
If a rolling body is kept on a surface of certain friction constant, does the...
Hi. I am doing an experiment on golf balls. I know that the dimples are supposed to reduce the resistance when traveling through the air. I am testing the effects that dimples have on rolling resistance when on the ground.
I am using 3 golf balls of the same type/brand.
One, I am keeping it...
Homework Statement
Describe how you could use the procedure from this experiment to measure the coefficient of rolling friction between the tires of a car and the road surface for different pressures of air in the tires?
Procedure =
1. Slide a mass along the surface of a lab desk and...
Homework Statement
Two bicycle tires are set rolling with the same initial speed of 3.60 m/s along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 psi and goes 18.7m ; the other is at 105 psi and...
Hello guys,
I would like to help me with rolling friction on a car(i am building a project that simulates the forces
applied to a vehicle when it moves on a straight road http://rapidshare.de/files/40862186/Vehicle_Sim.zip.html).
So:
Engine has a torque at some RPM,and the torque goes...
Homework Statement
An Airbus A320 jetliner has a takeoff mass of 75,000 kg. It reaches its takeoff speed of 82 m/s in 35s.
Find the Thrust of the engines, don't worry about air resistance, but rolling friction is substantial.
Homework Equations
Fnet=mass*acceleration
a=(82/35)...
Hello,
I was wondering if someone could check math that determines rolling friction please.
Basically I have been into Wikipedia doing a bit of research and put the following math together. The output of the function looks about OK against some test drives in my car, rolling a bottle across...
Hello,
I am writing a simple programme and need a function for friction acting on a rolling sphere and I am not sure how to go about it so can you help please.
The environment will be a sphere rolling across a horizontal surface of friction f at a velocity of.v and I wish to compute the...
Does anybody have a table of rolling friction coefficients? I can't find the one I'm looking for. I have a vertical door opening (similar to a garage door) where there are UHMW polymer rollers rolling in a track. I read somewhere that the coeff of rolling frict would be close to teflon on...
[SOLVED] Force Problem
The total mass is 2300kg (weight = 5072lbs). Find the size of the force due to wind and rolling friction when the van speed is 42.17mph (1mph= 0.447m/s).
This is the graph: http://capa-new.colorado.edu/msuphysicslib/Graphics/Gtype12/prob09a_1004minivan.gif"
F = ma...
Homework Statement
The graph shows the speed as a function of time for a minivan, coasting on neutral along a straight, level road, loaded with windsurfing equipment and towing a boat.The total mass is 2450kg (weight = 5402lbs). Find the size of the force due to wind and rolling friction when...
Homework Statement
Two bicycle tires are set rolling with the same initial speed of 3.00 along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 and goes a distance of 17.2 ; the other is at 105 and...
[SOLVED] Rolling Friction
Homework Statement
Rolling Friction. Two bicycle tires are set rolling with the same initial speed of 3.30 m/s along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 psi...
Rolling Friction?
Can someone explain to me why the frictional force is in the same direction as the acceleration of the center of mass of a rolling object?