Rolling Definition and 1000 Threads

Rolling is a type of motion that combines rotation (commonly, of an axially symmetric object) and translation of that object with respect to a surface (either one or the other moves), such that, if ideal conditions exist, the two are in contact with each other without sliding.
Rolling where there is no sliding is referred to as pure rolling. By definition, there is no sliding when there is a frame of reference in which all points of contact on the rolling object have the same velocity as their counterparts on the surface on which the object rolls; in particular, for a frame of reference in which the rolling plane is at rest (see animation), the instantaneous velocity of all the points of contact (e.g., a generating line segment of a cylinder) of the rolling object is zero.
In practice, due to small deformations near the contact area, some sliding and energy dissipation occurs. Nevertheless, the resulting rolling resistance is much lower than sliding friction, and thus, rolling objects, typically require much less energy to be moved than sliding ones. As a result, such objects will more easily move, if they experience a force with a component along the surface, for instance gravity on a tilted surface, wind, pushing, pulling, or torque from an engine. Unlike cylindrical axially symmetric objects, the rolling motion of a cone is such that while rolling on a flat surface, its center of gravity performs a circular motion, rather than a linear motion. Rolling objects are not necessarily axially-symmetrical. Two well known non-axially-symmetrical rollers are the Reuleaux triangle and the Meissner bodies. The oloid and the sphericon are members of a special family of developable rollers that develop their entire surface when rolling down a flat plane. Objects with corners, such as dice, roll by successive rotations about the edge or corner which is in contact with the surface. The construction of a specific surface allows even a perfect square wheel to roll with its centroid at constant height above a reference plane.

View More On Wikipedia.org
Recent contents Top users
  1. H

    Magnitude of Final Angular Speed of Rolling Sphere

    Homework Statement A block with mass 2 kg is hanging from a string that goes over a solid disk pulley with mass mdisk = 2 kg and radius Rdisk = 0.3 m with tension T1=11.34N between them. The other end of the string is attached to a massless axel through the center of an sphere on a flat...
  2. K

    Can a heavier car reach higher top speed rolling down a steep?

    Hi everybody, The question is that we have two cars with similar specifications except that one of them is heavier than the other. I was told that the heavier car can go faster on a steep because of more weight. Is that true?
  3. B

    LOG: Understanding Car Crash Velocity and Acceleration Calculations

    I'm trying to figure out what information I'm lacking that I need and what formulas to use in order to calculate velocities and accelerations in a car crash. For the first part of the crash, it was a sideways slide in grass, and I've got that part. Then the side wheels catch and the car starts...
  4. D

    Binomial Distrubition/Die rolling Question.

    How to Find the Probability of rolling at least 2 "sixes" in 6 rolls of a balanced die. I am trying to solve using the Binominal Formula, P(X = r) = nCr p r (1-p)n-r But am not really sure what the probability rates for success and failure should be or how to compute it. Any advice? Thanks.
  5. A

    Uniform solid sphere rolling on inclined plane

    Homework Statement A uniform solid sphere,rolls without slipping on a horizontal surface with an angular velocity \omega,meets a rough inclined plane of incination 60(degrees).The sphere starts pure rolling up the plane with an angular velocity.Find the new angular velocity . Homework...
  6. A

    Paradox of Rolling: Exploring the Conflicting Forces on an Ideal Wheel

    When an ideal wheel rolls without slipping on a horizontal floor there is a frictional force exerted at the instantaneous point of contact between the wheel and the surface in the opposite direction to motion. But this frictional force does no work on the moving wheel because the point of...
  7. B

    Idea of Rolling, Rotation, and Transition

    I'm very confuse about the idea of applying Newton's law of forces and torques on rolling body. The book shows that you can separate the situation in rolling into pure transition and pure rotation. However, what I don't get is, for the calculation of Newton's 2nd law of forces on pure...
  8. T

    Can a Ball Slide Rather Than Roll Down an Accelerating Inclined Plane?

    Is it possible to make the coefficient of friction between a ball and an inclined plane low enough so that a ball will silde down the plane and not roll down the plane?
  9. S

    Rolling Cans: Hypothesizing the action inside

    Hi peeps of this forum. I'm having trouble analyzing the results of an experiment, and it'd be great if I could get some pointers. Thnx :) The experiment: There are two cans. One is broth, aka viscosity is very low. One is cream soup, aka viscosity is very high. The two cans have the same...
  10. R

    Static, kinetic and rolling friction when rounding a flat curve

    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...
  11. P

    Cylinder rolling down an inclined plane

    Homework Statement So I have this standard problem of a cylinder rolling down an inclined plane, however, this time the plane itself is free to slide on the ground. I need to find the acceleration of that cylinder relative to the plane. 2. The attempt at a solution...
  12. R

    Why Does Static Friction Cause Torque in a Rolling Ball?

    Homework Statement a solid metal ball of mass M and radius R is rolling without slipping down and incline. A static friction force of magnitude f is acting on the ball. What is the magnitude of the torque due to static friction? a.) zero b.) rfcos theta c.) rfsin theta d.)Rf e. MRF...
  13. R

    How Do You Calculate Acceleration with Rolling Friction and Force?

    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...
  14. H

    Quastion about parallel robot with rolling pairs

    hi are every one know about parallel robot with rolling pairs for example one sphere rolling pn the fixed sphere. my quastion is the application of this structure. tnx hossein
  15. H

    Solving Spherical Rolling Problem - Hossein

    hi , every one! I have a problem with a sphere rolling on a fixed sphere. My problem is to find relationship between coordinate of center of sphere (X,Y,Z) and orientations (alpha, beta, gamma) or Euler angles of sphere. as we know a sphere has 6 DOF in space (3 coordiantes and 3 rotation) when...
  16. K

    Rolling down a slope vs to slide down a slope

    Consider the rolling cylinder in the figure To describe the cylinders translational motion, I have Ma=G sin \theta - f a is the acceleration of the cylinder parallel to the slope. If you have an object (cylinder or not) sliding down the same slope without friction, with the same...
  17. C

    What Are the Correct Terms for Rolling Wheels vs. Rolling Balls?

    Greetings, I have a peculiar terminological issue. In a research paper I am writing, I need to distinguish between rolling wheels and rolling balls. The relevant difference for my purposes is that a wheel rotates around a single axis whereas a ball rotates around a single point. It's...
  18. P

    Calculating Acceleration of a Rolling Wheelbarrow

    A wheelbarrow is released from rest and, with constant acceleration, goes down a hill. Between 3seconds and 5seconds, the displacement is 12m, and between 9s and 11s, the displacement is 48m. What is the acceleration? i'm not sure how to do a question where the intervals are not beside each...
  19. T

    Exam Question: Rolling Ball on Concave Surface - Is Work Done?

    Homework Statement A question I had in an exam today, just wanted to see whether it was right: A ball is rolling down the inside of a concave surface. The radius of the ball and the curvature of the surface is such that there is no slide. Is work done by a) the friction force b) the Normal...
  20. D

    Disagreement: Who is Right About Rolling Wheel Forces?

    I am in a disagreement with someone on another forum. There is wheel with a freewheeling hub constrained to roll on a particular surface by applying force to the hub in the horizontal x direction. This person claims the tangential force applied to a wheel from the surface will also act on the...
  21. H

    Rigid body rolling along an inclined plane

    Homework Statement So rigid body (ring, cylinder, sphere), who's radius of gyration is known, rolls down an inclined plane without slipping. Find velocity as a function of height. m - mass of the body. y0 - initial height, g - gravitational acceleration, v - speed. I - moment of inertia, K -...
  22. I

    Kinetic Energy of two Rolling Objects on a Slope

    Hi everyone, not a homework problem, just something I was thinking about when I found in a book. Homework Statement A hollow Cylinder is rolling down an incline of angle theta. Inside the cylinder is a smaller solid cylinder rolling freely inside it. (Refer to diagram) Given an x...
  23. M

    Rolling motion of a cylinder down an incline

    Homework Statement Assuming smooth rolling with no resistance, it can be shown that the acceleration of a solid cylinder down an incline is equal to: a = 2/3 g sin(theta) The goal of my lab is to test the validity of the above equation Homework Equations The Attempt at a...
  24. B

    Rolling motion in a special ramp

    Homework Statement Assuming the sphere roles down without sliding prove that the acceleration of it's center of mass is: a= \frac{g\cdot \sin(\theta)}{1+\frac{2}{5}\cdot \frac{1}{1-\frac{1}{4}\cdot \xi^2}} Where \ \xi=\frac{L}{R} Note that the moment of inertia of the sphere is...
  25. R

    Sphere rolling down an incline rotational kinetic energy

    A small diameter (2.00 mm), solid steel ball rolls from rest, without slipping, down a track and into a loop-the-loop of 1.50 meters diameter. Between the starting point on the track and the top of the loop the ball converts 10.0% of its initial mechanical energy into other forms of energy. From...
  26. S

    Calculating Probability of Rolling a 3 before a 7

    Can I get some help with this? You have two dice. What is the probability of rolling a "3" total before rolling a "7" total?
  27. D

    Particle rolling on a circular path

    Homework Statement At the end of the lecture in http://ocw.mit.edu/OcwWeb/Physics/8-01Physics-IFall1999/VideoLectures/detail/embed13.htm , Prof. Walter Lewin compares the motion of a slider on a circular air track (no friction) with the motion of a ball on a circular path (with friction)...
  28. P

    Another ball rolling down the ramp

    Another "ball rolling down the ramp" i've looked through the physics forum without finding the problem solved.Homework Statement I want to compare theoretical and practical data, with a ball "rolling" down a ramp. the problem comes when i try to measure all the factors, so far the things i...
  29. J

    Pigeohole principle - rolling die

    Well I know that P.P says that for m objects, and n boxes, where m > n, there must be one box of n that contains at least two or more objects. It seems simple, but the application is not. So for the given problem, like a There are 6 sides for a single die. And I thought I should do 6^2...
  30. M

    Cold Rolling Reduction Calculation Troubleshooting: Negative Signs Explanation

    I have some difficulties on calculating the reduction on cold rolling process but mi signs is negative. Is that normal? Cheers
  31. J

    Dynamics of a Rolling Wheel on a Sliding Platform

    Hi, I have a problem that I am working on and I am running into some questions. The question states (the image is attached): This system consists of the disk D and the bar B that is welded at point Q. The other end of this bar is fixed at point O. Assume that the disk rolls on the thin...
  32. S

    Does a Rolling Cylinder Have One or Multiple Angular Rotations?

    If a cylinder is rolling without slipping, C is the centre of zero velocity for a moment and O is the centre Does the angular rotation about O equal to the angular rotation about C, or is there only one angular rotation when a cylinder is rolling, that is the rotation about the point of...
  33. M

    Ball rolling down smooth curve

    Ball sliding down smooth curve Homework Statement A mass of 2 kg is dropped vertically into a frictionless slide located in the x-y plane. The mass enters with zero velocity at (-5,5) and exits traveling horizontally at (0,0). Assuming the slide to be perfectly circular in shape construct a...
  34. J

    Find the Height of an Inclined Plane for a Rolling Disk

    1. The problem statement, all variables and given known data A solid disk of radius 1.60 m and mass 2.30 kg rolls without slipping to the bottom of an inclined plane. If the angular velocity of the disk is 4.9 rad/s at the bottom, what is the height of the inclined plane? Homework...
  35. Q

    Conservation of energy, Rolling without slipping.

    Homework Statement A bowling ball is rolling without slipping up an inclined plane. As it passes a point O it has a speed of 2.00 m/s up the plane. It reaches a vertical height h above O before momentarily stopping and rolling back down. Determine the value of h. The moment of inertia of a...
  36. M

    Bowling ball rolling - velocity, acceleration, time

    Homework Statement A bowler throws a bowling ball of radius 11.0 cm along a lane. The ball slides on the lane with an initial speed of 8.10 m/s and an initial angular speed of zero (i.e. the ball is not spinning at all when it first makes contact with the lane). The coefficient of kinetic...
  37. M

    Tire rolling down slope - angle - friction

    Homework Statement Suppose the hoop were a tire. A typical coefficient of static friction between tire rubber and dry pavement is 0.88. If the angle of the slope were variable, what would be the steepest slope down which the hoop could roll without slipping? The Attempt at a Solution...
  38. A

    Sphere rolling down an inclined plane

    I've seen a number of posts on the following question, but don't believe any contain a solution to the following very simple scenario: A sphere of radius r and mass m rolls down a plane inclined at theta degrees. What are its linear and angular velocities at any time t thereafter, assuming it...
  39. silvermane

    Calculating Probability of Rolling Yahtzee

    If you’ve ever played the game of Yahtzee, you’ll know that often times, the last line to be filled in is YAHTZEE. Let's say I want to calculate the probability of rolling Yahtzee on a single turn. To this end, suppose that after you roll five dice, you are allowed to select any of the five dice...
  40. S

    Rolling on an Incline: Will a Sphere Continue Pure Rolling?

    Homework Statement A smooth inclined plane with inclination \theta is fixed in a car accelerating on a horizontal surface with a=gtan(\theta).A sphere is set pure rolling on this incline. Will it continue pure rolling? The Attempt at a Solution My idea is to find the linear...
  41. K

    Solving Rolling Friction Homework: Angular Speed

    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...
  42. C

    How Do You Calculate the Acceleration of a Board on Rolling Tubes?

    Homework Statement Plank of mass M = 8 kgr is installed on the same two tubes (very small thickness) radius R and mass m = 2 kgr. Initially the system property. A horizontal force F = 40 N applied to the board and the tubes rolled without sliding (Ic = mR^2). When the board shifted s = 2m on...
  43. V

    Rolling together percentages probabilities

    Hi, Wondering if you gals/guys could help me here. For simplicity sake, say you have slot machine. To win the game all four balls must appear in four slots. Three of the balls are blue and one red. The 2nd slot is reserved for the blue ball. As for the red balls, they can only appear in the...
  44. S

    Force of Friction in rolling motion without knowing r

    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...
  45. 1

    Solving Rolling & Slipping Homework Problem

    Homework Statement "A 0.18-kg billiard ball whose radius is 2.8 cm is given a sharp blow by a cue stick. The applied force is horizontal and the line of action of the force passes through the center of the ball. The speed of the ball just after the blow is 3.9 m/s and the coefficient of...
  46. R

    Will the Cart Roll Down the Hill Despite Friction?

    Homework Statement An 0.80-kg cart rolls down a 30.0° hill from a vertical height of 0.50 m. The distance that the cart must roll to the bottom of the hill is 0.50 m/sin 30.0°=1.0 m. The surface of the hill exerts a frictional force of 5.0 N on the cart. Does the cart roll to the bottom of the...
  47. L

    Projectile motion of a rolling ball

    Homework Statement a ball rolls off the top of a stairway with a horizontal velocity of magnitude 1.50m/s. The steps are 20cm high and 20 cm wide. Which step will the ball hit first?Homework Equations d = v1t + at^2 a = -9.8m/s^2 t= 2viSinθ/ 9.8 horizontal displacement = vi^2Sin2θ/ 9.8 The...
  48. J

    A Ball Rolling : What forces are involved?

    Let's say that a basketball was rolling on a road. A completely level road. A road that wasn't downhill or uphill, just straight. So, as its rolling, what forces are working against it? I'm thinking of 3. Gravity and friction. Also wind resistance. Am I correct? Would the wind resistance be an...
  49. J

    What Is the Acceleration of the Bottom Point of a Rolling Object?

    Homework Statement The point on the bottom of a rolling object is instantaneously at rest (v = 0). What is the acceleration of that point? Homework Equations The Attempt at a Solution The formula given is a = \alphar, and r = 0. So I'm guessing it's zero as well, although that...
  50. A

    Quesiton on applied force on a rolling object

    Hi guys, I thought of something when I was rolling something. In a nut shell, why is it easier to roll an object once it started rolling, and what would be the force required to keep the object rolling? Let's use a car as an example, when you push the car, it will only start rolling once...
Back
Top