Rolling Definition and 1000 Threads

Ok so a ball starts moving to the left while the rotation is clockwise, hence the backspin. On this surface there is friction. So clearly as the ball moves to the left, there is Kinetic friction to the right slowing down the Vcm and the spin as well. So assuming that the initial backspin is...

Hello - I am hoping for a bit of helping on a high school science project. I am looking for suggestions on how to force water through a tube or a screen within a barrel full of water as it rolls. I had a concept for using a UV light system to purify the water, but that option fell apart so I...

for a disck rolling on a horizontal plane the kinetic energy should be the kinetic energy of the CM of the disk with respect to the origin plus the kinetic energy due to the rotation of the disc about his CM so T= 1/2 (M V^2) +1/2(I ω^2) where M is the mass of the disk and V is the velocity of...

Homework Statement A 120 kg hoop rolls along a horizontal floor so that its center of mass has a speed of 0.240 m/s. How much work must be done on the hoop to stop it? Homework Equations I of hoop=MR^2 The Attempt at a Solution KE=0.5*m*v^2+0.5*(mR^2)(v/R)^2...

Homework Statement A sphere of mass M and radius R is not necessarily solid or hollow. It has moment of inertia I = cMR^2 . The sphere starts from rest and rolls without slipping down a ramp from height H. It then moves back up the other side with height h, but now with no friction at all...

A sphere is rolling inclined wall (θ radian). and the momentum of that sphere is L = 1/2 mv^2 + 1/5 mv^2 + mgx sin(θ) = 7/10 m v^2 + mgx sin(θ) ∂L/∂v = p 7/5 m v = p but I can't understand why the factor of mv is 7/5. p is the linear momentum of sphere. which means the factor of mv must be...

I'm a bit confused. We all know that rolling with slipping is associated with kinetic friction. But Is that friction due to the traslational motion of the center of mass or just the spinning motion?If friction exists because of the translational motion, then in theory, I can slowly lower a...

kuruman submitted a new PF Insights post Explaining Rolling Motion Continue reading the Original PF Insights Post.

http://imageshack.com/a/img923/733/FJKAqj.jpg so here is the deal. is rolling resistance N+Ft or are they "separate" in a means of: N part is for static friction = mu*N and Ft is part of rolling resitance=coefficient of rolling resistance*Ft so that in order for tire to start rolling without...

what is the different between rolling in a straight line without slipping and with slipping and which topic it take these type of motion

Hello, I play bowls on outdoor grass greens. I studied physics in school, and I've been wondering how physics works on the bowls in different areas of the green. So for those who aren't familiar, you have a jack and a bowls. Jack is smaller and lighter, bowls larger and heavier. The bowling...

Homework Statement A solid cylinder is attached by a rope on its center.It has mass of 5kg and is lying on a table.The other end of the rope is a block of mass m2 which is not on the table .if the coeficient of friction between cylinder and table is 0.2.Find the maximum mass 2 so that the...

Im starting to learn about vehicle dynamics by watching video lectures here , and also reading the books by Gillepsie and Jazar. I´ve got a fundamental question about the FBD of the vehicle. According to Gillepsie :http://imgur.com/a/lGXxw http://imgur.com/a/lGXxw The vehicle is...

I am sorry for drawing up very old and closed posting https://www.physicsforums.com/threads/rolling-friction.150891/ but I saw this question many times and I can not understand why do not people simply use well-known theorem which says that power of the forces which are applied to a rigid body...

Homework Statement http://moodle.telt.unsw.edu.au/pluginfile.php/1602233/question/questiontext/1933161/1/1188262/Screen%20Shot%202014-04-03%20at%2011.21.21%20am.png[/B] A disc has radius r<<R and mass m = 7.8 g. When released, it rolls on its edge without skidding on the track in the sketch...

Homework Statement A cylinder of mass m and radius R is set on a plane, with large enough friction coefficient to ensure at any moment rolling without slipping. A constant torque is applied along the axis passing through the center of mass (G) of the cylinder and perpendicular to the basis of...

Homework Statement A snowball, initially of mass m, slides down a slope inclined at an angle φ with respect to the horizontal. As it moves, the mass of additional snow Δm = αx that it accumulates is proportional to the distance traveled x. Write the differential equation of translational motion...

Hi! Well, I'm programming a vehicle's physics, and I have trouble finding a way to calculate Rolling resistance, though i searched a lot. I already have the Traction Force and the Drag Force, but now I need Rolling Resistance. The best thing i found is that Froll = Croll * P, where Croll is the...

1. Assume there is gravity and no external force acting on the system. A ball has an initial velocity of 5 m/s and climbs up a parabolic ramp, which is defined by y=(x^2)/3. If the ball rolls exactly along the path of ramp and energy of the ball is conserved, starting from (0,0), calculate the...

Homework Statement The image above shows a basketball (a thin spherical shell I=⅔ mR^2) rolling don an incline of height 8.4 m. If the ball is already rolling with an initial linear speed of 3.0 m/s then what will be the final linear speed when it rolls off the incline? Homework Equations I =...

Homework Statement [/B] I have two cylindric reels laying on the ground. They are identical: mass M, composed by a cylinder of radius R and two side cylinders of radius 2R. I have to find angular acceleration and work done by F in delta t. 2. The attempt at a solution On the first cylinder...

Homework Statement Homework EquationsThe Attempt at a Solution O is the center of the disk Part a) The emf induced across PS can be found by thinking as if a rod PS is rotating and translating . The component of velocity of rod perpendicular to its length is vsin45° = v/√2 . The length PS...

Homework Statement http://imgur.com/0t8TVgq http://imgur.com/0t8TVgq [Image copy inserted by moderator] Sorry about all the erase marks. My question is why is the final velocity not 0. Homework Equations V=Vo+at[/B] The Attempt at a Solution So the question is asking for the horizontal...

So if a ball is rolling down a ramp and not slipping, you have two torques... the mg*sin(theta) portion of gravity and the (mu)mgcos(theta) for friction. My question is this: Does this friction force remove energy from the ball? (I know it affects the balls rotation but this is just changing...

I'm confused about this rolling without (or better with) slipping situation. Suppose to have a disk with initial velocity ##v## and angular velocity ##\omega##. The motion is to the right but the angular velocity is counterclockwise. There are no forces acting on the disk besides the kinetic...

<<Mentor note: Thread split from https://www.physicsforums.com/threads/torque-opposite-in-direction-to-change-in-angular-momentum.866882/>> it can be proved that in this case pure rolling without slipping is impossible ive assumed the cone to be right circular proof by contradiction...

This isn't about a specific physics problem, but rather a question: Given I have a ball or cylinder rolling smoothly along some path, is it generally true that mechanical energy is conserved? I.e. if ##E_mech = K+U = K_{trans} + K_{rot} + U##, then ##\Delta E_mech = 0##? I have been able to...

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...

From the last few sentences of the below attached paragraph, when the inertia ellipsoid is prolate, the body cone rolls outside the space cone; when it is oblate, the body cone rolls inside the space cone. Whether the body cone rolls outside or inside the space cone should depend on whether the...

Homework Statement A sphere (of radius r and mass m) rotating with angular velocity ω0 is lowered onto the edge of a floating platform of length L and mass M. The platform can move freely on water. The platform is rough and the sphere rolls all the way from one edge to the other edge of the...

I'm sure this is elementary for this forum, but can someone help me figure out if my son's science fair project results are correct? He rolled his toy car, with and without weight added, down hill and measured the time to get to the bottom of the hill and the distance traveled once the car hit...

Homework Statement Hi everybody! Here is a classical mechanics problem about a ball (mass m, radius r) rolling down a slope (from height h) and going through a loop-the-loop. a) What is the minimum height h from which the ball must roll in order to successfully complete the loop-the-loop...

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...

Homework Statement "A ball of moist clay falls 15.0 m to the ground. It is in contact with the ground for 20.0 ms before stopping. (a) What is the magnitude of the average acceleration of the ball during the time it is in contact with the ground? (Treat the ball as a particle.) (b) Is the...

Homework Statement Rolling without slipping A) Derive the linear acceleration vector equations for points A, B, C, and O in terms of R, ω, α and θ at this instant. B) R = 0.5 m, ω=-54 r/s and α = 0. Determine the MPH of the vehicle and the vector accelerations of points A, B, C, and O. C) R...

Homework Statement A ball is rolling along a frictionless hemisphere with radius R. The question asks about when will the ball rolls off the hemisphere. I understand that this happens when the normal force vanishes. But I am also wondering what if the normal force provided by the hemisphere...

Homework Statement A solid ball of mass M and radius R and moment of inertia I is placed onto a table with an initial velocity v_0 to the right and angular momentum w_0 anticlockwise (i.e the ball has backspin). Due to friction, the angular velocity and linear velocity changes as the ball both...

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...

Homework Statement (i) Suppose there's an object rolling without slipping at any surface. (ii) Now, let's say a disk is rolling and slipping toward the +x direction 2. The attempt at a solution (i) If the surface is horizontal then it won't apply any friction force on the object regardless on...

Homework Statement I am tasked with finding the theoretical final speed of a car rolling down a hill using energy calculations. I am given the angle of the incline, the height of the ramp, the length of the hill (horizontal and actual length) and the mass of the car. Also, the car is starting...

Homework Statement There are two problems: (A) Consider two identical billiard balls (spheres), each of mass M and radius R. One is stationary (ball 2) and the other rolls on a horizontal surface without slipping, with a horizontal speed v (ball 1). Assume that all the frictional forces are...

Does rolling friction depend on the surface area? In other words, the size of the object placed? If I had a block and sphere of the same mass. Without static and kinetic friction coming into play. Which would experience greater rolling friction if they were on the same incline and of the same...

Homework Statement There is an empty bottle described as an hollow cylinder, that lies on a paper. Now the paper is pulled with an acceleration a, so that the bottle starts rolling perfectly on the paper. (Have a look at the figure.) Homework Equations Calculate the acceleration of the center...

Homework Statement [/B] A thin light string is wrapped around a solid uniform disk of mass M and radius r, mounted as shown. The loose end of the string is attached to the axle of a solid uniform disc of mass m and the same radius r which can roll without slipping down an inclined plane that...

Homework Statement Doing this from a memory of a final exam question from freshman physics that I could not solve 45+ years ago. A coin of radius R is poised at the top of another (fixed) coin of radius 2R. If it rolls with no slip, at what point will the top coin leave the lower coin. (I...

Homework Statement A sphere of radius .06 m and mass .5 kg rolls down a ramp that is angled 30 degrees down the incline. It starts rolling from a height of 7 feet and does not slip What is its final linear velocity? Now, I used mgh=translational +rotational KE and found that the final velocity...

Homework Statement A billiard ball is imparted a horizontal impulse of 2 N*s at a height 4 cm above the center of the ball. The mass of the ball is 0.02 kg and it has radius 5 cm. Find velocity of the center of mass right after the impulse. Note: I simplified the question, I was actually given...

Homework Statement Mountaineers are simulating a massive avalanche snowball by using a big Styrofoam ball (m = 75 kg; r = 1.50 m).They give it an initial impulse of 1500 kg m/sto start it rolling down the hill without slipping (no snow sticks to the ball, and ignore air resistance). Near the...

Homework Statement Hoping to outdo his physics professor, Doofus wants to dramatically demonstrate parabolic motion by throwing a cheese wheel of massm and radius r off of the top of the UW observatory, which is at a height 3R above the roof of the physics building, as shown in the diagram...

Homework Statement A hoop has a mass of 200g and a radius of 25cm (ICM = MR2 ). It rolls without sliding along level ground at VCM = 5m/s. What is it's total kinetic energy? Homework Equations K = 1/2Iω2 ICM = MR2 v = rω The Attempt at a Solution The answer is 5J, but I'm getting 2.5J. ICM...