Angular velocity Definition and 866 Threads

  1. ashraful

    Acceleration in circular motion

    Homework Statement In the case of circular motion,the direction of the velocity is changing in every moment.So,there is a angular accelleration here.What is the direction of this accelleration? Homework EquationsThe Attempt at a Solution
  2. Jonski

    What is the Angular Velocity of Gear 5 in a Differential Gear System?

    Homework Statement Gear 2 in the figure below is driven at a speed of 80 rpm in the CCW direction viewed from the right end. Gear 4 meshes with a fixed ring gear (gear 7) and with gear 5. Find the angular velocity of gear 5. N2= 16 T, N3= 32 T, N4= 30 T, N5= 22 T and N7= 77 T. Homework...
  3. K

    Calculating Angular Velocity and Linear Acceleration in a Speed Skater's Curve

    Homework Statement A speed skater increases his speed from 10 m/s to 12.5 m/s over a period of 3 seconds while coming out of a curve of 20 m radius. a. What is the magnitude of his angular velocity as he leaves the curve? Be sure to include proper units for your answer. b. What is his average...
  4. D

    How Is Centrifugal Force Calculated for a Particle in a Rotating Frame?

    Homework Statement A particle of mass ##m## rotates about ##Z-##axis in a circle of radius ##a## with a uniform angular speed ##\omega##. It is viewed from a frame rotating about the ##Z-##axis with a uniform angular speed ##\omega_0##. Find the centrifugal force on the particle. Homework...
  5. ChrisBrandsborg

    Rotational motion: playground spinning disk problem

    Homework Statement A child is at a playground, and chooses to try the spinning disc (see figure). The radius of the disc is 2.00 m, and the coefficient of static friction between child-surface and disc-surface is μs = 0.350. In the following questions, you must provide algebraic equations as...
  6. S

    Angular Velocity in Linear Momentum Equation

    m1v1 = m2v2 v = rω m1(rω)1 = m2(rω)2 m1ω1 = m2ω2 Does this make sense?
  7. moenste

    Reaction on the particle in terms of angular velocity

    Homework Statement A particle is attached by means of a light inextensible string to a point 0.4 m above a smooth horizontal table. The particle moves on the table in a circle of radius 0.3 m with angular velocity ω. Find the reaction on the particle in terms of ω. Hence find the maximum...
  8. lorenzo99

    Angular Velocity of a trebuchet

    Hello, I need some help regarding angular physics. I am working on a project and I want to be able to predict (to some degree) the velocity of the payload leaving the trebuchet. (Excuse my ignorance I am just a high school student) Lets say a trebuchet see diagram has a counter weight m1...
  9. Mr Davis 97

    Maximum angular velocity so that there is no stick

    Homework Statement We have a concrete mixer, and if the drum spins too fast, the ingredients will stick to the wall of the drum rather than mix. Assume that the drum of the mixer has radius R = 0.5 m and that it is mounted with its axle horizontal. What is the fastest the drum can rotate...
  10. H

    I Does small angle mean small angular velocity?

    Why is the term ##(\sin\theta\,\dot{\theta})^2## fourth order in the small ##\theta##, as claimed by the sentence below (5.108)? By small-angle approximation, ##(\sin\theta\,\dot{\theta})^2\approx\theta^2\,\dot{\theta}^2##. For this to be fourth order, it seems like we must have...
  11. Z

    How to derive linear velocity from position and angular vel.ocity

    Hello! I'm trying to derive the linear velocity vector from the position vector and the angular momentum vector. I've seen on the internet that V = W x R (V,W and R are all vectors and x is the cross product) but I cannot for the life of me derive it! I've tried doing it by writing out the...
  12. D

    Angular velocity of an atom in a magnetic field

    Homework Statement The orbit of an electron (-e) around a nucleus (Ze) is a circular orbit of radius a in a plane perpendicular to a uniform magnetic field \textbf{B}. By writing the equation of motion in a frame rotating with the electron, show that the angular velocity \omega is given by one...
  13. B

    Two Rotating Disks Contacting Along Edge

    Homework Statement Two disks, rotating in the opposite direction of the other, are held together on their rotating ends, acting as toothless gears. The bottom disk is slightly skewed in one direction, and therefore causes a frictional force on the top disk, and thus an equal and opposite force...
  14. D

    Angular velocity of circular orbit, small oscillations

    Homework Statement The potential energy of a particle of mass m is V(r) = k/r + c/3r^3 where k<0 and c is a small constant. Find the angular velocity \omega in a circular orbit of radius a and the angular frequency \omega' of small radial oscillations about this circular orbit. Hence show...
  15. S

    Fluid in rotating tube with different initial levels

    Homework Statement Homework Equations Fluid in rotation The Attempt at a Solution This exercise is quite different from the classic one of fluidi in rotation. Before rotation starts the height in one branch is bigger than in the other, so I do not really know how to approach the problem...
  16. H

    Problem in Classical Mechanics

    Homework Statement I am stuck over a classical mechanics problem. I tried to solve it, but after having solved the first point, I got stuck on the second one. Here is the problem: >A mechanical structure is composed by 4 rigid thin bars of length $\ell = 8\ m$, mass $m = 5\ kg$ each one. Those...
  17. Matt Benesi

    Change in angular velocity of the following system

    The pink spheres cause an acceleration of 1 cm per second squared towards themselves. The aqua spheres cause an acceleration of 2 cm per second towards themselves. All spheres have the same mass. The spheres are attached to a massless, yet mysteriously solid perfectly circular green...
  18. P

    Angular velocity of suspended rod

    Homework Statement A uniform rod of length L & mass m is suspended through an end. It is shifted through an angle of π/2 radian i.e. made horizontal and then released. Find angular velocity when rod is vertical.[/B]Homework EquationsThe Attempt at a Solution My attempt to a problem is attached...
  19. N

    Understanding Angular Velocity Calculations for Rotating Objects

    Homework Statement Homework Equations v = w x r The Attempt at a Solution I got the answer correct after a few tries, but I am little confused on why it has to solved this specific way. I know that v = w x r, so why can I not just say w = v/r? Is it because w is measured from the center of...
  20. AntoineCompagnie

    Why is velocity in body fixed frame equals to angular veloc?

    Homework Statement I don't understand, physically speaking, how do we get from the first equation to the second: how do we get the fact that velocity in body fixed frame equals to angular velocity in body fixed frame. Furthermore I dont' understand how we get the angular velocity in inertial...
  21. slick_willy

    Why does atmosphere rotate w/ constant angular velocity?

    Hey guys. I've seen this question asked on a few different forums, and I understand the basic gist of the answer but I am not yet satisfied with what I have read. People seem to have varying degrees of understanding of this, and I am the type of person that wants to understand things 100% and...
  22. I

    How to calculate moment of inertia of this irregular system?

    hello all, I am currently doing a lab investigating the relationship between the moment of inertia and speed. I have attached some pictures of my 'wheel' that is going to be rolled down a ramp. FYI i will be using a photogate to measure the time it takes the black strip to pass through...
  23. D

    Dynamics of Rotational Motion and hinge

    One end of a thin, uniform rod is connected to a frictionless hinge as shown in Figure 1. The rod has a length of 0.8 mand a mass of 2 kg. It is held up in the horizontal position (θ=90∘) and then released. 1)Calculate the angular velocity of the rod at θ=90∘. 2)Calculate the angular...
  24. N

    Angular velocity and acceleration

    Homework Statement Small mass sits on a circular revolving table, 200 mm from center. It is given a constant angular acceleration of 2 rad/s. The static coefficient of friction is 0.2. At what angular velocity will the mass start to slip? Homework Equations ar=v2/r ar=r''-rθ'2 aθ=rθ''+2r'θ'...
  25. R

    Finding the Spring Constant: Angular Velocity vs Hooke's Law

    So I'm doing an experiment where I am using five different methods to find the spring constant of a spring. These three values of k should be the same but alas, they are not :( and I am at a loss as to why. The first method was by using hooke's law and finding the displacement and graphing the...
  26. Tom MS

    B Does the Coriolis Effect Occur When Wind Moves Horizontally?

    I'm trying to get an understanding of the Coriolis effect, and I understand it when the wind moves longitudinally (North-South). Basically, the wind has a certain horizontal component of its velocity due to the rotation of the Earth, and as it moves North or South the rotation of the Earth...
  27. S

    Angular momentum conservation and constant velocity as expla

    I'm confused about situations involving rotating frames in which the angular momentum is conserved and the initial velocity does not change. I'll make an example. Take a rotating carousel (constant angular velocity) with no friction on it and a ball. At the initial time instant the ball has the...
  28. D

    Angular Velocity and Acceleration

    Homework Statement If a bike wheel rotates 9.4 times while slowing down to a stop from an initial angular velocity of 8.1 rad/s, what is the magnitude of the angular acceleration in rad/s/s Homework Equations α = at / r α = ω / t α = Θ / t^2 ω = Θ / t ω = v / r Θ = ω t + 0.5 α t^2 v final = v...
  29. D

    Angular Velocity and Acceleration graph

    Homework Statement A.) For the graph above what is the angular displacement during the 4 seconds of motion? B.) For the graph above what is the angular acceleration from t=2 to t=4? Homework Equations α = at / r α = ω / t α = Θ / t^2 ω = Θ / t ω = v / r Θ = ω t + 0.5 α t^2 The Attempt at a...
  30. D

    Angular Velocity and Acceleration

    Homework Statement A car is traveling at 27.8 m/s, it undergoes a negative acceleration of 2.6 m/s/s when the brakes are applied. How many revolutions will the tires go through before the car comes to a stop if the wheels each have a radius of 1.0 m? Homework Equations α = at / r...
  31. kev931210

    Stochastic dynamics and Angular velocity of a molecular motor

    Homework Statement Homework Equations Langevin equation (I included all the equations in the next section.[/B]The Attempt at a Solution I do not know how I can proceed from this point. I'm stuck since I have no information on the drag coefficient. Maybe my approach is wrong, and there may...
  32. George_J

    Torque & Inertia calculation for a wheel

    Hello! Before I start I want to apologize for my english and not having a scanner (lol). I'm calculating the torque needed to rotate a wheel* around its own axis from above, ( see the link at the end of post). I have quite an good idea to how I'm supposed to calculate it but I feel that...
  33. S

    Component of angular momentum perpendicular to rotation axis

    Homework Statement Consider the rigid body in the picture, rotating about a fixed axis z not passing through a principal axis of inertia, with an angular velocity \Omega that can vary in magnitude but not in direction. Find the angular momentum vector and its component parallel to z axis (...
  34. S

    Torque on barbell when angular momentum is not constant

    Homework Statement [/B] Consider a barbell with two equal masses m that rotates around a vertical axis z not passing through its center with angular velocity \vec{\omega}. The barbell is forced to stay in this position by an appropriate support. Identify the forces exerting torques on the...
  35. S

    Torque on rigid body when angular momentum is not constant

    I 'd like to clarify some doubts about the rotational motion around a fixed axis of a rigid body, in the case the angular momentum vector \vec {L} is not parallel to the angular velocity \vec {\omega} . In particular, consider a horizontal barbell with two equal masses m , forced to rotate...
  36. L

    Falling rotating sphere and displacements

    Homework Statement Homework Equations How to locate the point P and C after 0.5s from their initial position ? The Attempt at a Solution Well i don't know whether it would be correct way to start the problem i.e find the centripetal acceleration .
  37. RoboNerd

    Question on ap physics c 2012 free response

    Homework Statement The problem is attached in the file "selection(1).pdf" The explanations/solutions are attached in "selections.pdf" which is below [Problem image - added by moderator to make it visible in-thread] Looking at how they solved part C, I have no idea why they say that the...
  38. S

    Rubber on a rotating disk (angular velocity, forces)

    Homework Statement We place a rubber on the edge of a rotating disk. What forces act on the rubber? At what angular velocity, why and in what direction will the rubber fly off the disk? Homework Equations http://images.tutorvista.com/cms/formulaimages/83/angular-speed-formula111.PNG The...
  39. Enochfoul

    How Do You Calculate Angular Velocity and Force in Rotational Motion?

    Homework Statement Hi Everyone would somebody please be able to give some advice on the following questions: Part (a) A body of mass m kg is attached to a point by string of length 1.25 m. If the mass is rotating in a horizontal circle 0.75 m below the point of attachment, calculate its...
  40. R

    Angular acceleration from angular velocity

    Hello everybody. I would really appreciate some help Homework Statement I have some problem where I have measured angular velocity data. This measurements are not equally spaced, meaning there were taken after some (variable) delay passed. I need to find what is the angular acceleration at...
  41. xpell

    B Relativistic tips of a propeller

    Hi! Yes, I know that faster-than-light travel is impossible. But please stay with me for a while to help me understand this. Let's imagine we take some unobtainium and build a 12-km-radius propeller, attached to an engine able to accelerate it up to 250,000 rpm (like a turbocharger, or not a few...
  42. G

    Angular velocity of falling box

    Hi, I'm preparing a computer software to simulate the fall of an object for an academic project. The object is rotating (not rolling) over the circular bottom point. I know that the angular velocity at the horizontal point is ω = √(3g/L). I would like to calculate the angular velocity at every...
  43. C

    Rotor blade thrust - torque and angular velocity

    Imagine a motor, spinning a rotor blade around and around and around and around and around... How does the angular velocity of the rotor blade, and the torque affect the thrust produced?
  44. K

    How Far Does a Hamster Run in Its Wheel in One Night?

    1. The problem statement, all variables and given/known A hamster runs in its wheel for 2.7 hours every night. If the wheel has a 6.8 cm radius and its average angular velocity is 3.0 radians per second, how far does the hamster run in one night? Homework Equations w= delta theta/change in...
  45. T

    Find the time for the string to break

    Hi all! I am currently working on an assignment for my dynamics course in which we need to create our own "real world" problems. I chose to do a problem which would solve the time at which the string of a lanyard would break when it is swung in a circle. My problem is with my end numbers. They...
  46. W

    Rotating disc of radius R spinning at constant angular velocity

    Ok, so here's the deal. I'm working on something that I SHOULD know the equations for after 5 years of school and a degree in mechanical engineering, but then again I can't remember why I walked into a room most times. So if ya'll could give me some guidance and at least a starting point I...
  47. X

    Phasor angular velocity for a triangle wave?

    What would the angular velocity for a phasor be for a triangle wave? I think it would vary sinusoidally but I can't find an expression
  48. C

    Ball rolling and slipping with backspin

    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...
  49. L

    I Are Special Relativity effects valid for angular velocity?

    I like a to ask a very simple question. I have read about time-dilation when it comes to SR. So, like: (1.) A and B are are rest and close to each other. (2.) B starts traveling at .5C relative to A, away from A, in a straight line. (3.) B comes back at .5C towards A. Now, according to SR, A...
  50. Mingsliced

    Offset Piston - Calculating Max. Angular Velocity

    Homework Statement After happily working my way through the earlier parts of this question, I'm pretty much at the end of my tether with the last two parts. Please find the diagram attached: A) Determine the value of the angle θ (measured from vertical) when the angular velocity of link AB a...
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