Angular velocity Definition and 868 Threads

Homework Statement The block at C is moving downward at vc = 4.8 ft/s. Determine the angular velocity of bar AB at the instant shown. Homework Equations x = cross product r = distance to point from frame of reference Boldface will indicate vectors v = ω x r vB = vA + ω x rB/A =...

This is not schoolwork. Imagine that light did not have a constant speed, but behaved in the manner expected from experience. Namely, if the source of the light is rushing toward you, the light will approach you faster; if the source is rushing away from you, the light will approach you slower...

Homework Statement A thin plastic rod of length L with total charge +q uniformly distributed along only the outer half-length is shown in Fig. 1. The rod is rotated at a constant angular speed w rad/sec about, and perpendicular to, the z-axis. Find the magnetic field B at the pivot...

So, I have been studying angular velocity and linear velocity--and I want to use this information determine if a ray intersects a plane. linear velocity = dp/dt angular velocity = dΘ/dt thus for linear velocity, you have a point in space: the intersection point could be described as I...

Greetings, I fell upon a certain question and it seemed that no matter what I did I was unable to solve it. I wished to know how if given a radius of 0.6m and the time for one revolution: 0.3s, to find the angular velocity in radians of the object. Consider it to be a point particle. Thanks

ω = dΘ/dt if any points on a uniform disc have the same angular velocity then the corollary implies that any point on the disc must transverse 2π rad in the same amount of time. Is there a mathematical way to demostrate this or is this only demostratable purely by experiement?

Hello, I have been trying to find an equation to represent the observed angular velocity of any object traveling in a straight path x and y distance away from where its being observed, along with the moving objects velocity. My problem is that I am getting a differential equation that in its...

The problem is to find out the maximum angular velocity that the swing carousel can spin at before the chain holding the passenger breaks. The maximum tension that the chain can withstand is known (T). The radius from the centre of the ride to the chain when stationary is known (r). The...

Homework Statement (a) Calculate the moment of inertia I of the disc when it rotates about the pivot as shown in the figure. (b) If the disc is released from rest, determine the angular speed, ω, of the disc at its lowest point. Homework Equations a) Id = Icm + md^2 Icm = 1/2*M*R^2...

The figure attached shows two masses held together by a thread on a rod that is rotating about its center with angular velocity w. If the thread breaks, the masses will slide out to the ends of the rod. How will that affect the rod's angular velocity. Will it increase, decrease, or remain...

Would someone be willing to explain this? Here: https://www.physicsforums.com/showthread.php?t=487058 I read the entire thread and don't understand. I need one person to explain it step by step all in one place. In my case it's not a homework question. Please don't use the Socratic method...

Homework Statement Hello, I am doing a mechanisms homework assignment in which a hydraulic piston moves out and moves a link connected to the piston in an angular fashion. I'm just a bit confused about the units of angular velocity and I feel very foolish asking this. Homework Equations...

Homework Statement A rod of length L and mass M is pivoted at the center C such that it can freely rotate in vertical plane.Initially the rod is at horizontal position.A blob of wax of mass M falls vertically with speed V and sticks to the rod midway between center and one end.If the rod...

There seems to be different types of angular velocity to me... 1) A rigid body could be moving in a nonlinear path (ex. a pendulum) 2) A rigid body could be rotating about an axis on itself (ex. the Earth rotating about an axis) 3) Both #1 and #2 combined (ex. the Earth moving around the sun...

Dear All, i was reading a book in which it is written that if a rigid body have both rotational(with angular velocity 'w' about its center of mass)and translation(with velocity 'v' of center of mass) motion then the whole motion can be treated as an equivalent motion of pure rotation about...

Homework Statement In reviewing my last physics exam I found the following statement in the posted solution: ...the derivative of \sqrt{\frac{3g}{l}(1-cos\theta)} is \frac{3g}{2l}sin\theta Homework Equations N/A The Attempt at a Solution This is from a physics course and I'm...

According to the wikipedia page, when given an angular velocity, centrifugal force increases with radius. I always thought the larger the radius, the smaller the centrifugal force. I think I'm misunderstanding some term here (possibly "angular velocity"). Can someone please explain?

This is more a question of understanding than physics:) I have two rotating wheels each with a given radius and a given mass, if one is rotating with an angular velocity and the other is stationary and the stationary one is brought into contact with the rotating one what is the common angular...

First off, I want to apologize for posting more than one question. I just discovered this site, so I wanted to check my work while I am able to. Thank you again. Homework Statement A massless rope of length L = 1 m is swung in the vertical plane, with a bob of mass m = 1 kg attached to its...

Homework Statement So ,here is the question : The structure is shown in the picture. All I need is to find the angular velocity of telescopic arm BC ,in this current position. http://img197.imageshack.us/img197/3954/w6e.JPG Homework Equations Well,them simple ω=rXv/r\bulletr...

Homework Statement A solid cylinder is rolling along a horizontal plane and is friction less around its symmetric axis. The cylinder is pulled by a constant force, F and travels the distance, d. The cylinder does not glide and has a friction force, f on the ground. Known values: Mass: M...

Homework Statement A guy is spinning on a chair with his hands at rest on his lap. As he is spinning, a large mass drops into his hands/lap. Does the guy continue spinning at the same rate, a slower rate, or a faster rate? This video demonstrates what happens when the guy drops mass...

Homework Statement A solid flywheel of radius R and mass M is mounted on a light shaft of radius r so that the axis of rotation is horizontal. A light, inelastic rope is wound around the drive shaft and is connected, via a light, frictionless pulley to a mass m, which is suspended a height h...

Homework Statement An Ice skater of mass m = 70kg is initially traveling at a speed v = 4 m/s along a straight path that brings his center of mass to within a distance b = .6m of a vertical pole fixed in the ice. He reaches out with his hand as he passes the pole and hangs on so that he pulls...

I've got 3 problems that I got wrong on my most recent test (college 1st year physics). I need to figure out what I did wrong and hopefully someone here can help me. I know all my answers are wrong because I got marked wrong but I'm unsure why, or if there's another way or a better way to go...

Homework Statement On a frictionless table, a 0.50 kg glob of clay strikes a uniform 1.58 kg bar perpendicularly at a point 0.38 m from the center of the bar and sticks to it. If the bar is 1.30 m long and the clay is moving at 6.60 m/s before striking the bar, what is the final speed of the...

Homework Statement http://puu.sh/57VmL.png A thin rod, 28.5cm long with a mass of 0.97kg, has a ball with diameter 7.81cm and mass 2.15kg attached to one end. The arrangement is originally vertical and stationary, with the ball at the top. The apparatus is free to pivot about the bottom...

Homework Statement The given figure shows a mechanical system free of any dissipation. The two spheres (A and B) are each of equal mass m, and a uniform connecting rod AB of length 2r has mass 4m. The collar is massless. Right above the position of sphere A in figure is a tunnel from which...

Homework Statement I am having a few doubts while writing relationship between angular speed and linear speed ,in the reference frame of a moving observer . Suppose at an instant, car A is heading towards car B with velocity 'v'. Car B is moving towards right with velocity 'u' ,i.e along...

Hi, I have two questions related to angular velocity: 1. According to rotational damper, Torque = Viscous Damping Coefficient * Angular Velocity. This equation gives the unit of Angular Velocity as meter square per second. How is it equivalent to rad per second? 2. If I have an angular...

Homework Statement A wheel rotating about a fixed axis with a constant angular acceleration of 2.0 rad/s2 turns through 2.165 revolutions during a 2.0 s time interval. What is the angular velocity at the end of this time interval? Homework Equations I was using the kinematic Equations...

An offset press cylinder has a $13.37\text {in}$ diameter. The linear speed is $\displaystyle\frac{16.53 \text{ ft}}{\text{sec}}$ What is the angular velocity $(\omega)$ in $\displaystyle\frac{\text{rev}}{\text {hr}}$ from $v=r\omega$ then $\displaystyle\frac{16.53\text{ ft}}{\text{sec}}...

Hi! I was wondering how you plot the sunspots on a diagram/template with degrees on it. In other words, I want to plot a sunspot and calculate the position of it in degrees. I have no idea how to do it but I think it includes the assumption that the rotation axis of the Sun is perpendicular...

A belt contects two pulleys with radii $\displaystyle5\text { in}$ and $3\text { in}$ the $\displaystyle5\text { in}$ pulley is rotating at $\displaystyle\frac{1000\text{ rev}}{\text{min}}$ What is the linear $\displaystyle\text{v}$ in $\displaystyle\frac{\text{ft}}{\text{sec}}$ of the belt...

Problem: Newton's 2nd Law for rotational motion states that the product of the moment of Inertia, I, and the angular acceleration alpha(t) is equal to the net Torque acting on a rotating body. Consider a wheel that is being turned by a motor that exerts a constant torque T. Friction provides...

Gear C has radius 0.12 m and rotates with angular velocity 1.9 k rad/s. The connecting link rotates at angular velocity 1.5 k rad/s. Gear D has radius 0.05 m. Find the angular velocity of gear D (in rad/s). Note that gear C is pinned to ground and gear D is a planetary gear. Since gear c...

Homework Statement The angular velocity of a process control motor is (21−(1/2t^2)) rad/s, where t is in seconds. 1.) At what time does the motor reverse direction? 2.) Through what angle does the motor turn between t =0 s and the instant at which it reverses direction? Homework Equations...

How exactly can the angular velocity of a 2 dimensional laminar object be the same with respect to all axes of rotation perpendicular to its plane ?

Homework Statement (a) A particle moves in a plane with constant radial velocity [(r)\dot] and constant angular velocity [θ\dot]. When the particle is at distance r from the origin, determine the speed of the particle. Data: [(r)\dot] = 3.2 m/s; [θ\dot] = 2.3 rad/s; r = 3.2 m. (b) When the...

Hello, If I apply force on a rigid cube, I can find the torque τ as: τ = F x r Now, from torque τ I can know about the axis of rotation but how much should I rotate the cube. How can I find the angular velocity ω from torque τ? Or is there any other way by which I can find how much the...

Homework Statement A concrete block is a uniformly dense cuboid of dimensions 40 x 20 x 10 cm, with mass M. It is constrained to rotate about an axis passing through two opposite corners and its centre of mass, with constant angular speed ω. Calculate the direction of the angular...

Homework Statement A circular cannister of some reflective liquid is spinning at some ω. The distance between the cannister and the surface is given by h(r) = h(0) + (ω2/2g)r2 Where g ≈ 9.82 and r is the distance to the axis of revolution. When we shine two parallell laser beams on the...

Is there a way to calculate angular acceleration from the change in angular velocity and the change in the angle without considering time? How would you accomplish this?

Homework Statement Two disks are rotating about an axis common to both. The first disk has moment of inertia I and angular velocity ω. The second disk has moment of inertia 2I and angular velocity \frac{ω}{2} Both rotate in same direction If both disks are pushed into each other what is the...

Homework Statement A girl is spinning on a chair and holding a paper bag so that it is horizontal, and perpendicular to the axis of the rotation. What should the girl's angular velocity be in radians per second, so that the bottom of the bag breaks? The girl's arm is 0.7m long. When...

hi, I've calculated ω=5 rad/s How can I calculate angular acceleration (α) I've Mass, M=4Kg Radius, R = 2m and time taken by each single revolution, T=3sec.

Hello, can anyone explain why the direction of angular velocity, acceleration, torque, and momentum point perpendicular to the rotation of the circle? It seems to make more sense if it pointed in the tangential direction.

Homework Statement Find the required angular velocity of the stick swinging around it's end axis (like a simple pendulum only without the added mass) at the point of "balance" (where the sinus function crosses the x-axis I suppose, sorry for the "weird" translation) so that it will be able...

First of all I am sorry for my awful english. Homework Statement Electric motor starts turning wheel with a constant power of P=25W and J=3 kg*m^2. With what angular velocity the wheel spins after 7s(from start), if the efficiency is 60%Homework Equations P=M*ω M=J*αThe Attempt at a Solution...

Homework Statement A dirtbike is being used to turn a merry-go-round with a 650 kg mass, and a radius of 2m, and can be treated as a rotating disk (I=1/2 MR^2). The dirtbike is applying a force of 3.00kN tangentially to the surface of the merry-go-round, in a continuous way. a. If the...