What is Roll: Definition and 179 Discussions

Rock and roll (often written as rock & roll, rock 'n' roll, or rock 'n roll) is a genre of popular music that evolved in the United States during the late 1940s and early 1950s. It originated from Black American music such as gospel, jump blues, jazz, boogie woogie, rhythm and blues, and country music. While rock and roll's formative elements can be heard in blues records from the 1920s and in country records of the 1930s, the genre did not acquire its name until 1954.According to journalist Greg Kot, "rock and roll" refers to a style of popular music originating in the United States in the 1950s. By the mid-1960s, rock and roll had developed into "the more encompassing international style known as rock music, though the latter also continued to be known in many circles as rock and roll." For the purpose of differentiation, this article deals with the first definition.
In the earliest rock and roll styles, either the piano or saxophone was typically the lead instrument. These instruments were generally replaced or supplemented by guitar in the middle to late 1950s. The beat is essentially a dance rhythm with an accentuated backbeat, almost always provided by a snare drum. Classic rock and roll is usually played with one or two electric guitars (one lead, one rhythm) and a double bass (string bass). After the mid-1950s, electric bass guitars and drum kits became popular in classic rock.Rock and roll had a polarizing influence on lifestyles, fashion, attitudes, and language. It is often depicted in movies, fan magazines, and on television. Rock and roll may have contributed to the civil rights movement because both African American and White American teenagers enjoyed the music.

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  1. Z

    Coin flip and dice roll question (check my answers?)

    Homework Statement Hi, I just wanted to check my answers for this question: Q: Suppose that we flip a coin six times and roll a 6-sided die once. Suppose also that all outcomes of this experiment (consisting of an ordered sequence of results for the flips (heads or tails) and the number...
  2. B

    Interpreting magnetic compass pitch and roll

    Hello all, I have a PNI TCM2 electronic compass module, which has a 3-axis magnetometer and a 2-axis tiltmeter (manual: http://www.mil.ufl.edu/projects/gnuman/spec_sheets/tcm2_man.pdf" ), and provides heading with tilt compensation. The module also provides "pitch" and "roll" measurements...
  3. M

    Does a bottle of water or a bottle of ice roll downhill faster? [Video]

    Before you watch the video, give your answer here... and why you think it's correct.
  4. H

    What is a roll center? (steady state cornering in a vehicle)

    I'm studying the chapter 'Steady State Cornering', from the book 'Fundamentals of Vehicle Dynamics' (by Gillespie). The concept of a 'roll center' seems to be very important here, especially after the 'roll axis' is defined (line joining the front and rear roll centers). But I don't...
  5. A

    Dummy proofing roll feed direction

    So here's the the problem. We have a number of laminating machines at my work and the machine operators occasionally put the product onto the unwind chuck in the wrong direction (i.e. clockwise rather then counter clockwise). We need a SIMPLE way to insure that this does not happen. I'm aware...
  6. N

    How is the roll centre used during braking?

    I'm calculating the weight transfer experienced by a car during braking, accelerating and cornering. So far i have been using moment equations with the centre of gravity height. I've used some suspension software to determine the roll centre and was wondering if this is meant to be used when...
  7. A

    Probability Distribution of Random Variable X from a Double Dice Roll Experiment

    The question is "An experiment in which a dice is tossed twice. Let X be the random variable defined by recording the higher of the 2 values obtained in the experiment. Determine the probability distribution of X." I know that the range of this distribution is {1,2,3,4,5,6}. For P(X=1) both...
  8. E

    Affect of Body Roll on Vehicle Cornering

    Homework Statement Not sure if this is the right place, it's a past paper problem - not really homework. Anyway, the question asks for the maximum velocity a car can take round a bend without sliding or rolling over. Radius of Bend = 60m (R) Friction Co-ef = 0.55 (u) Width of car, (tyre...
  9. M

    Standard deviation of a dice roll?

    Let's say I have a big, 50-sided die, with values ranging from 1-50. I want to find the exact standard deviation of the dice roll by hand. I would like to avoid subtracting the mean from each possible value, if at all possible. How do I do that?
  10. O

    Average amount of die rolls to roll a specific number

    Hi, I know very little about maths. I'm struggling to get my head around a question I was asked today, and I was wondering whether someone could explain it to me. Question: If a very large group of kids took it in turns to roll a die again and again until it landed on '1', on average how...
  11. F

    Medical What causes some people to want to roll their head

    Ever since I was a very young child I have rolled my head while laying in bed. I don't roll my head the entire time that I am awake, but I do roll my head a lot.
  12. dkotschessaa

    Roll a 13 using 2 ordinary dice

    Originally posted on another forum with the title "are some things impossible?" The question was more of a philosophical one, but it got me thinking mathematically. I thought I had a solution like this: Put die #1 in a base 5 numbering system, you get the following values for the 6 rolls...
  13. S

    How far up the hill will it coast before starting to roll back down?

    Homework Statement A car traveling at 22.0 m/s runs out of gas while traveling up a 24.0deg slope. How far up the hill will it coast before starting to roll back down? Homework Equations (v_final)^2 = (v_initial)^2 + 2*(a_parallel)*(x_final - x_initial) ...and some trig The Attempt...
  14. M

    How Many Licks Tootsie Roll Help

    "How Many Licks" Tootsie Roll Help 1. Homework Statement [/b] In an activity, i was supposed to determine the rate of change of volume of a tootsie rool as i consume it. My initial radius is 1.21 cm at t=0 sec the rest of my data is 30 sec- 1.27 cm 60 sec-1.25 cm 90 sec- 1.24 cm...
  15. G

    Finding Velocity and Angular Speed of a Rolling Cylinder

    Homework Statement A solid cylinder of radius 20cm is released from a 2.5 high incline. If it rolls down without losing any energy to friction, find the cylinder's velocity at the bottom of the incline and the angular speed at the bottom of the incline. Homework Equations The...
  16. U

    How to estimate roll position via gyroscope data?

    im trying to implement a tilt sensing program via accelerometer and gyroscope. part of the input that i will plan on using is gyroscope data. since gyroscopes measure angle/sec, integrating this will give me angle right? i then have three questions: 1. do i multiply the gyroscope's (1/sampling...
  17. J

    Is a Vibrating Structure Gyroscope the Key to Measuring Vehicle Pitch and Roll?

    Hello everyone, i'm new to this forum and this is my first post. My question is: how to get pitch and roll of a moving vehicle using an 3-axis accelerometer? accelerometer values are the same when vehicle is stopped? Thanks in advance.
  18. T

    Extracting yaw, pitch, roll from transformation matrix

    There are two references frames, A and B. Let A's reference frame be denoted by the columns of the identity matrix, and let A's origin be (0,0,0). Let B's reference frame and origin be denoted by a transformation matrix T, where T = R11 R12 R13 x R21 R22 R23 y R31 R32 R33 z 0 0 0 1...
  19. U

    How do i find roll angle with using acceleration vectors?

    Homework Statement Assume that the z-axis is pointing up, x-axis is along the horizontal, y-axis goes from "front to back". How do i find the roll angle using 3 acceleration vectors with respect to each of the 3 axes (ax,ay,az) , that is (with respect to each other only something like...
  20. K

    Accelerometer to roll and pitch

    hi how can i convert accelerometer vector to quaternion and then convert it to pitch and roll? i want full 360 degrees of roll and pitch
  21. C

    Do things roll on frictionless surfaces?

    I was solving this question in rotational mechanics (not asking for help). The author then goes to solve this using energy conservation, equating the final kinetic and rotational energy to the initial potential energy. Now, he obviously assumed the object rolled on the surface, which, if...
  22. Loren Booda

    The greatest poets of Rock & Roll

    In my opinion, Rock & Roll offers great music, but not so great lyrics. Who, like Bob Dylan, bucks the latter trend?
  23. J

    Roll 14 dice, take the highest 7

    I was playing a pencil and paper role playing game with some friends, and some questions came up about the what is most important to increase to get better at a skill. There are two values for each skill- the basic value and your training value. The basic value ranges from 1-7 and determines how...
  24. R

    What angle to pull the yo-yo under so it doesn't roll?

    Homework Statement The yo-yo is made of two wheels, connected by a short beam (the cross-section of the beam looks like the letter "H"), around which wire is wrapped up. Let the yo-yo be stationary on a desk. What is the angle ß in relation to the said desk (see picture) that we must gently...
  25. P

    The catamaran tank - an MRAP which doesn't roll over

    OK so that is the problem and there is an obvious vehicle modification to counter the roll-over problem which is to fit stabilisers, adopting the same concept employed in a child's bicycle. http://img3.imageshack.us/img3/3770/stabilisedmrap.jpg The simplest and cheapest way to do this...
  26. R

    Robotics Yaw Pitch Roll Euler Angles

    I have multiple robot cells that i would like to move fixtures from robot to robot with the out come of the part to be perfect. in order to do that i need to make sure my work object is in the same spot each time. so i need to find the yaw pitch and roll and convert them into Euler angles. On...
  27. C

    Puzzling roll X dice, choose Y highest problem

    Puzzling "roll X dice, choose Y highest" problem Hi folks, Over the past few days, a friend and I have been wracking our brains over a dice throw probability problem. As the post title describes, it's simply rolling X dice and picking the Y highest (we coined the notation 'xky' for 'roll x...
  28. S

    If I roll a hoop forward, what keeps it up?

    I've seen the gyroscopic effect explained in terms of angular momentum, but I feel that there should be a much more tangible and easily understood solution - one that would make sense to a person without any understanding of algebra. Specifically, I'm looking for an explanation that looks at...
  29. M

    Canadians: Ready to Roll Up the Rim and Win with Your Coffee?

    Lately, I've been liking my coffee with a Roll-up-able Rim. You may need to be Canadian to get it (and probably need to be Canadian to win!) http://rolluptherimtowin.com/
  30. D

    How Far Did the Cannonball Roll?

    Homework Statement In 1453, during the siege of Constantinople, the Turks used a cannon capable of launching a stone cannonball with a mass of 5.40 x 10^2 kg. Suppose a soldier dropped a cannonball with this mass while trying to load it into the cannon. The cannonball rolled down a hill...
  31. S

    Calculation of vehicle pitch rate and roll rate from acceleration

    I have to estimate the pitch rate and the roll rate of a vehicle, from measured accelerations. I have many three axial accelerometers. How can i accomplish it?
  32. G

    Do heavy and light cylinders roll the same?

    I understand why a heavy item and a light item both fall a given distance in the same time - in a vacuum, etc. What happens in the case of a cylinder rolling down an inclined plane with no slippage? Would a heavy cylinder reach the bottom at the same time as would a light cylinder? What if...
  33. M

    Estimating Label Quantity on a Used Roll

    Not sure whether or not I have posted in the correct forum or not, anyway this is my problem. At work we have no way of estimating how many labels are left on a roll before returning them to the warehouse. the average roll diameter is 8" with a 3.5" core diameter and the roll web has a single...
  34. G

    How to roll AISI 304 Stainless Steel

    We were asked in our Manufacturing Processes class to design a process for the manufacture of AISI 304 stainless steel sheet. Starting with hot rolled sheet 9 gauge (U.S.G.) in thickness and 32” wide. The final product is required to be 30 gauge (U.S.G.) in thickness and 32”. Our design needs...
  35. V

    Rollover Risk: Will a Car Tip Over if Centre of Gravity Changes?

    Will a car roll over if there is a change in centre of gravity?
  36. C

    Solving a Ball Roll Down a Slide: Velocity at Bottom

    Homework Statement A toddler is having fun rolling a ball down a slide of height h=4 m. The ball can be considered as a thin spherical shell, Icm=(2/3)mr^2, with m being its mass and r being its radius. What is the velocity of the ball at the bottom of the slide...
  37. J

    Can you derive a formula for the critical angle when pulling a thread roll?

    Homework Statement Hello, the question itself is pretty abstract. When pulling a thread roll, there is an critical angle, where the thread does not start to unwind itself. Instead, the thread roll itself starts to move. Derive an formula for determining that critical angle. Homework...
  38. O

    Fluid viscosity in a can and tendency to roll

    How does the viscosity of a fluid in a circular can affect the way the can rolls? For example, 2 cans of similar size, volumn, and mass are rolled down a ramp with the same slope. The can with a viscous liquid will take more force to begin rolling than a can with a less viscous liquid, but once...
  39. Phrak

    How do I make homemade sushi without a rolling mat?

    A couple of months ago I bought a rice cooker to make rice for sushi. All the ingredients we found (well, my wife found) at the supermarket after a couple tries: To make cucumber and crab rolls for a first time we bought 2 lb. white rice 1.2 oz toasted seaweed wraps 2 long cucumber 8...
  40. P

    Perfect Ball on Perfectly Frictionless Ramp - Does it Roll or Slide?

    Homework Statement Does a perfect ball roll or slide down a perfectly frictionless ramp? Homework Equations The Attempt at a Solution Let P be the contact point of the ball with the ramp. Then it appears to me there is a torque (about the contact point, P) acting on the ball due...
  41. V

    How Much Torque is Needed to Overcome an Obstacle with a Rotating Wheel?

    Hi to all Please help me to clarify this situation: There is a rotated wheel on a plan surface. What torque/power will be necessary to spring an obstacle with a concrete height. For ex. here are some data: 1.Wheel mass 10 kg 2.Wheel radius 0,3 m 3.Rotation speed 100 RPM 4.Obstacle...
  42. L

    Probability dice roll Question

    Hello! I need help on yet another probability question.. Question: A red dice has the number 1 on one face, the number 2 on two faces and the number 3 on three faces. Two green dice each has the number 6 on one face and the number 5 on five faces. The three dice are thrown together...
  43. P

    How long does the wheel slip before it begins to roll without slipping?

    Homework Statement A wheel with rotational inertia I = 0.5MR^2 about its central axle is set spinning with initial angular speed w and is then lowered onto the ground so that it touches the ground with no horizontal speed. Initially it slips, but then begins to move forward and eventually...
  44. T

    Proving Multiple Roots of a Function Using Roll's Theorem: A Scientific Analysis

    question : suppose that to the quadratic equation x^2+px+q=0 has two roots x_1<x_2 prove that for \frac{\mathrm{d^n} }{\mathrm{d} x^n}[(x^2+px+q)^n]=0 there are n different roots on the interval (x1,x2) ?? the prove: by rolls theorem we have a point "c" on the interval of...
  45. Loren Booda

    What are some commonly misheard lyrics in rock 'n' roll songs?

    What lyrics have you previously attributed to songs which you later learned were otherwise? For instance, I heard: "They proceeded to tear the whole town down." (Actually "...hotel..." from We're an American Band, by Grand Funk Railroad.) For instance, I heard (the most famous tuneout?)...
  46. P

    Modeling Kinetic Energy of a Ball Roll Experiment

    Homework Statement explain how an experiment where you let the ball roll from a certain height only models dropping a ball and finding its kinetic energy just as it hits the ground Homework Equations KE=PE 1/2mv^2=mgh i don't think you need to utilize these equations The Attempt...
  47. T

    I want to roll a ball on a material to get the latgest static charge in the ball

    But I don't know what is the best material to use for a ball and flat surface. I was thinking glass ball and typhlon tape at one point, but I have no idea. Can a rolling ball, roll over a surface and get a charge? with the very low friction? any insight on this, please help.. :smile:
  48. K

    How to find roll, pitch yaw

    how to find roll, pitch yaw... given an x,y,z position for the end of an robot arm(end effector), is there any way to find the roll, pitch and yaw for it...Given access to entire history of x-y-z positions. I'll be using IK then to evaluate whether these values are possible or not. All I need...
  49. I

    Torque requirements to roll vertically?

    Hi, I'm trying to model a problem about rolling up a wire. I don't know how to go about setting it up to calculate the Torque required to climb at a given speed. Obviously coefficients of friction, normal forces, and weight will all play a roll but am hoping I can get a hand setting up the...
  50. P

    Can a ball roll down a frictionless plane?

    I have posted this question before but have not got a complete answer. I have since been thinking about it quite often, yet still have not had a conclusive answer. I'd really appreciate if someone can give a full explanation, since it is a fact known by most. 1. Under all ordinary conditions...
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