What is Roller: Definition and 313 Discussions

Roller skating is traveling on surfaces with roller skates. It is a recreational activity, a sport, and a form of transportation. Roller rinks and skate parks are built for roller skating, though it also takes place on streets, sidewalks, and bike paths.
Roller skating originated in the performing arts in the 18th century. It gained widespread popularity starting in the 1880s. Roller skating was very popular in United States from the 1930s to 1950s, then again in the 1970s when it was associated with disco music and roller discos. During the 1990s, inline outdoor roller skating became popular. Roller skating has often been a part of Black and LGBT history in particular.
Sport roller skating includes speed skating, roller hockey, roller derby, figure skating and aggressive quad skate. It is also widespread as a hobby.

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  1. Crazy Old Coot

    Ring roller power

    In principle, the ring is, at any instant, a beam being loaded in the centre, and in a failing state. Thus, to drive the material continuously through the rollers, Force x Velocity = Work done/time = power. 60.P/2.pi.N = T The units pan out, but is the concept correct? The faster the work is...
  2. JackLee

    Find the force acting on the roller in the direction of the spring

    A torque meter with a triangular slab extension is inserted into a corresponding triangular slot. The C-shaped arm features a V-shaped dent on which a roller is seated. This roller is held in compression by a spring. The roller's positions are labeled '0' for the initial state and '1' for the...
  3. jayf202

    Can SKF Bearings and Housings Be Replaced by FAG Types?

    Hi there, i need your help. I want tom know if is it possible to replace a Bearings and a housing from SKF by a FAG type?
  4. A

    How to obtain Axial Load Capacity from Tapered Roller Bearings Catalog

    Hello there, I'm trying to select a tapered roller bearing (TRB) for my actuator, I know the peak axial force that is going to come. I have some radial load as well. I want to select the TRB based on the axial load, but all the bearing catalogs or most of them give Dynamic and static Load...
  5. V

    Automotive Calculating radial and axial loads for a tapered roller bearing

    Hi I'm analyzing a tapered roller bearing as part of a differential. I know the shaft is providing input torque of 333.5 N-m @ 4000RPM, and I know the bore size of the bearing, 30mm. I need to find the radial and axial forces given that torque, so I can move on to finding C10, L10, rated load...
  6. A

    Roller coaster and centripetal acceleration

    See attached image. The solution to this problem calculates v2 at the top of the roller coaster ride. Why is that? Shouldn't you calculate v2 at the bottom of the roller coaster ride as you require the maximum velocity there to get around the loop?
  7. 1

    Why did my roller luggage's wheels stop turning smoothly?

    Two weeks ago, my carry on worked perfectly. But last week the detachable wheels stopped rotating smoothly, when I tried to glide my carry on. The wheels budge JUST A TAD when you push them hard, but it should be EFFORT LESS! Please see two pictures below. I see nothing jammed in the wheels. I...
  8. Ineedhelpwithphysics

    Speeds of the rolling ball at different points in this roller coaster track

    For this question i tried to reason with my self that C was the fastest and A was the second fastest. B would be the third fastest and D would be the least fastest since the ball has to go up. I looked up the answer and it says that C is the fastest , B and D are equal, and A is the slowest. How...
  9. S

    Finding lower and upper limit for time related to roller coaster

    height from ground speed 100 40 80 48 60 60 40 72 20 80 I tried to plot the points (speed on x-axis and height on y axis) and I got more or less like a straight line but I am not sure whether the graph would help to calculate the upper and lower limit of the time. I also tried to...
  10. Purpleshinyrock

    Help me solve this equation please -- Roller Coaster Motion

    Hello. Can someone tell me what area of phisics should I study to better understand this exercise( I ve been looking at kinematics since it asks for the velocity but I can't seem to find where it talks about different points like this) and also what should I do to solve this exercise please? A...
  11. J

    Understanding the Work-Energy Theorem: Solving the Roller Coaster Problem

    height to point A is 65m. no friction. comes to rest at point A. total mass of the roller coaster is 650 kg. the work-energy theorem states that the net work done on an object is equal to the change in kinetic energy of the object. kinetic energy is E=1/2mv^2. initial velocity is...
  12. Stephen Bulking

    Identifying Pin Joints & Rollers - Structural Analysis Homework Help

    Summary:: I am doing my structural analysis homework and I can't seem to identify between pin joint and roller. Please take a look at the following exercises and help me understand: 1) In exercise 6.87, the joint at C is a pin joint whereas in exercise 5.63 the joints at the casters are...
  13. J

    Stainless Steel track surface grade to match a 440C roller?

    I have a machine I am designing that has a carriage supported by Track rollers on a machined flatbar track. The load that each individual roller will experience could reach 2000lbs. worst case scenario. The track surface is machined 304L - 1" wide as you can see in the green in the attached...
  14. G

    Is Gravity the only force doing work on a roller coaster cart?

    Why I think gravity *is* the only force doing work on the rider: 1) The only forces acting on the rider are gravity and the normal force. Broken down into their component vectors, we have: -> The component of the force of gravity moving parallel to the rider's direction of motion -> The normal...
  15. meso

    Physics roller coaster question

    I am stuck at C and D. I tried to solve D by applying W= delta E W= Etotal F x d= 11172000 F= 11172000/7 But I am not sure if it is right
  16. J

    Roller Coaster Loop Problem

    So, we know that at the bottom of the loop, the car will have a normal force pointing upward and gravity pointing down. However, I have discovered that the normal force is apparently greater than the force due to gravity. Basically N = F(g) + ? What is this other force?
  17. M

    B Can I keep multiple clocks in sync after a ride on a roller coaster?

    Suppose there are 6 cars on a roller coaster and I synchronize 6 clocks at rest with respect to each other in a box with no wiggle room on the space station. The bottom of the box has the same shape as the curvature of the earth, and the box is always kept "top side up" with respect to the...
  18. E

    G-force diagram on a roller coaster?

    So, while we were going up the track, the z-direction gforce seemed to go up. It went from -1 to about -0.6. The x-direction seemed to be around 0, more or less? All x values were under 0.177. The y-direction decreased, more or less, from -0.4 to -0.9. I think if I understand how the force...
  19. B

    Automotive EV hub motor torque for pulling a roller

    I am working on a 500 kg roller, which I want to pull using electric motor. I am considering hub motor, since it is easier to frame a basic ev with it. Now I need to know the capacity of the hub motor, I need to choose. Roller weight = 500 kg Frame weight + driver weight = 150 kg speed required...
  20. J

    Speed at the top of an elliptical roller coaster loop

    Homework Statement This isn't really a homework but a project I'm doing that's due soon. In our multivariable calculus class, we're creating a 3D roller coaster, and I need to explain the physics behind the roller coasters. For a roller coaster loop, if it were perfectly circular, we would...
  21. A

    Roller Coaster Force Question

    Homework Statement :[/B] A child of mass 40.0 kg is in a roller coaster car that travels in a loop of radius 7.30 m. At point A the speed of the car is 15.0 m/s, and at point B, the speed is 15.6 m/s. Assume the child is not holding on and does not wear a seat belt. What is the force (in N) of...
  22. P

    Electrical About a load calculation -- Roller selection for a plate straightining maching

    i am making a plate straightining maching for 25x2100 mm plate. motor- 30 hp and 960 rpm worm reduction gear box- 100:1 Please tell me about the selection of roller by which i can straight the plate, and gear also.. if center distance between gear is 280 mm

    Child Safe - RTS motor - roller shutter - shelf shutter

    Greetings Sir, I have a motorized RTS roller shutter (which can be controlled by both hand held remote controller Or wall switch) . The thing is when the motor detects an object, it will put its entire weight on the object and then stop (which means it will suffocate that "object"). Hence we can...
  24. Y

    Roller coaster problem involving velocity

    Homework Statement A roller coaster reaches the top of the steepest hill with a speed of 7.0 km/h. It then descends the hill, which is at an average angle of 43° below horizontal and is 46.0 m long. What will its speed be when it reaches the bottom? Assume the coefficient of kinetic Friction...
  25. J

    Uniform Circular Motion of Roller Coaster

    Homework Statement Assume the roller coaster cart rolls along the curved track from point A to point C under the influence of gravity. Assume the friction between the cart and track is negligible. What would be the direction of the carts acceleration at point A? (The question in the image does...
  26. S

    Automotive Motor Selection for Roller: Diameter 300mm, Length 1350mm, Inertia 3.95 KG.M

    i need to select the motor for a roller of Diameter 300mm , length 1350mm having inertia 3.95 KG.M ,Which needs to accelerate from 0 to 600MPM at 20 sec . Assuming existing web tension acting on the roller 20 N/M. THANK YOU
  27. Aireve

    Measure of spring in system with roller

    Homework Statement m1= 0,05 kg, m2= 0,03 kg, mass of spring is omitted. We look at movement after spring stopped vibrate. How long does the spring measure during the movement if not stretched spring measure 0,1 meter and if we use force 0,1N elongation measures 0,02 meter. (sorry, English isn't...
  28. C

    Critical Velocity in a roller coaster cart

    1. The problem statement, all variables, and given/known data I was just wondering if a roller coaster can still pass through a loop with less than critical velocity/energy (Also if I'm assuming critical energy correctly). The loop can be of any size yet it must not exceed 5.7g at the entry...
  29. H

    Conservation of Energy for a roller coaster

    Homework Statement If it can be assumed that the car has the same speed at points A and E, which of the following statements is true? a. The net work done in this system is 0 b. The net work done in this system is positive c. The net work done in this system is negative d. The net work done in...
  30. O

    I Modeling a peristaltic roller pump

    Hello! We were recently introduced to mathematical modeling. I would want to model a blood roller pump - a simple peristaltic pump. I was wondering, what kind of formulas there are that I can use to model a pump which optimizes the number of rollers, roller diameter, tube diameter etc...
  31. M

    Mechanics question: Roller passing over a step

    Homework Statement A gardener pulls a roller of mass 85 kg over a step. The roller has a radius of 0.25 m. The handle is attached to an axle through the centre of the roller at an angle of 45 degrees to the horizontal. Here's a link to the diagram below, it's figure 1 and 2 on question 18...
  32. Schaus

    Roller Coaster Physics: Calculating Energy, Speed, and Force

    Homework Statement Jessie (m=56.2 kg) is traveling at a speed of 12.8 m/s at the top of a 19.5-m high roller coaster loop. a) Assuming negligible losses of energy due to friction and air resistance, determine Jessie's total mechanical energy at the bottom of the loop (h=0 m). (ans: 1.53 x 104...
  33. J

    Minimum safe height for a roller coaster

    Homework Statement Based on the height of a first hill (114.5m), mathematically determine the minimum height (circular motion and radius) of the next hill based on the speed generated on the first hill. At the bottom of the first hill, the velocity of the roller coaster is 47.38m/s. There is...
  34. R

    Roller coaster physics conceptual question

    Homework Statement For my high school physics class we made roller coasters out of card stock with various loops and funnels. We then had multiple questions to answer. I couldn't seem to figure this one out. Why does the power have to be found at the bottom of the loop? Explain in terms of...
  35. N

    Roller coaster for a golf ball

    I have to make a roller coaster for a golf ball. It has to be made out of recycled materials. This also means no materials for construction (but chicken wire is allowed) and no prefabricated materials (Legos, Kenex, etc) 2 loops, 2 hills. Each hill has to be 20 cm height change. Can anyone...
  36. J

    Roller coaster/water rides/theme park designer

    Would someone withe a bachelors in civil engineering and a masters in structural engineering have a good chance at getting a job designing water rides, roller coasters, and theme parks?
  37. JustinT

    A different type of roller coaster loop problem

    Homework Statement A roller coaster at the nearby amusement park Physics Hill, has a large circular loop where cars travel at the top of the loop at 25.0 m/s causing the riders to enjoy an acceleration of 3g. Assuming the height of this loop is the same as the diameter, how high is the loop...
  38. K

    Replace a Track roller bearing with a Sleeved Bush bearing

    Hi. I have issue of continuous failure of Track roller because of excess loading. I am looking for bush bearing with bearing pressure with 150 to 200 MPa @ 0.144 m/sec sliding speed & Friction coefficient shall be max 0.1. I will install a sleeve on the bush bearing & use it as a roller . Can...
  39. C

    Gradient at roller and pin support

    Homework Statement in the notes , why did the author only stated that zero displacement occur at pin and roller support? Why the author didnt stated that the slope at pin and roller support is also = 0 ? Homework EquationsThe Attempt at a Solution As we can see from the figure, the gradient...
  40. J

    Engineering Water ride / roller coaster designer?

    What major would you study for a job like that, I'm hoping for someone to say structural/ civil/ architectural engineering because that's what I'm looking into but I've heard that its more mechanical or electrical engineering.
  41. R

    What is the minimum kinetic energy for this roller coaster ride?

    Homework Statement A rollercoaster has a loop with a radius of 12m. The coaster travels 50m and at point A, enters the loop. The average frictional force on the coaster is 40N. The mass of passenger is 50kg. What is the minimum kinetic energy required at point A to generate a velocity of 27m/s...
  42. B

    Measuring Friction at a curved surface

    Hi, if I have a block of metal with a quarter circle curve cut out of it, and a metal roller of matching radius that contacts this curved piece, what are some ways I could go about measuring the friction between these two surfaces? The roller is fixed and the block is pushed into it with a...
  43. D

    Simulated circular motion on a roller coaster

    Homework Statement A roller coaster at the Six Flags Great America amusement park in Gurnee, Illinois, incorporates some clever design technology and some basic physics. Each vertical loop, instead of being circular, is shaped like a teardrop. The cars ride on the inside of the loop at the top...
  44. L

    Exploring the Roller Coaster Ride of LIGO Photons

    I am trying to understand how the photons in the LIGO beams behave when going along the "slopes" of the gravitational waves, in particular how the Shapiro delay gets factored into the resulting interference. To simplify the situation, suppose that a LIGO photon starts orthogonally to a wave...
  45. M

    Roller coaster - uniform circular motion

    Hi, I have been studying up on circular motion in the vertical plane and I am happy with all the math/theory that I have read explaining the normal force and weight force and the feeling of being "heavier" and "lighter". My question is about the top of the hill/ride, The forces acting on you at...
  46. L

    Friction between roller coaster and track

    Homework Statement A roller coaster is going down on a track (see image below, the track itself is highlighted in red) without initial velocity. What is the coefficient of friction between the roller coaster and the track? height at which the cart starts (h) = 12m weight of the car (m) = 620kg...
  47. Rumplestiltskin

    Roller Coaster Physics: How to Calculate Maximum Velocity on a Horizontal Plane

    Homework Statement [/B] b) Calculate the maximum velocity of the empty carriage at D. (3 marks) Homework Equations /[/B] The Attempt at a Solution 750 x 9.8 = 7350 N No clue. Can't use SUVAT on the vertical plane to find time because v = u = 0 from peak/trough to peak/trough. Horizontal...
  48. L

    Safe speeds in roller coasters

    From my research and understanding of roller coasters, their speed is mainly impacted by the force of gravity and it works on the basis of potential energy build up into kinetic energy. Therefore, my question surrounds the idea of safe speeds on coasters. Because a roller coaster car is only...