Rotating Definition and 1000 Threads

Not sure if this should be in quantum section, please move if necessary. We know that: 1. A stationary particle with charge q is not affected by an external magnetic field. We can assume this particle is not magnetic at all, since it would allign and travel in relation to the magnetic...

Homework Statement I am having difficulties with finding the acceleration at A. In the picture above are the questions that I need help with.

Homework Statement A homogeneous rod with a length L and a mass M rotates with an angular velocity ω in a horizontal plane around an axis passing through its end.Find the tension of the rod at a distance x from its axis of rotation .Homework Equations The Attempt at a Solution...

Homework Statement y = {\frac{1}{4+x^2}} on the interval [0,2], revolving about y = -1 Use either the disk/washer or shell method to find the volume. Homework Equations v = pi\int (outer radius)^2-(inner radius)^2\,dx v = 2pi\int (radius)(height)\,dy x = \sqrt{\frac{1}{y}-4}...

I came across the following example. I have a mass m' that is suspended from a massless rope which is wound around a drum of mass m. The radius of the drum is R. The drum is fixed on a shaft with bearings of radius r. I am supposed to determine coefficient of friction between the bearings and...

Hi suppose i had a ball on string and started to rotate it in a circle around my hand. When i increase the speed of the ball it becomes more and more horizontal. The only forces i can think of at play is centripetal and centrifugal forces and the force exerted by my hand and gravity. Is somehow...

This is a conceptual problem which I am facing for many days. If we convert a scenario in an inertial frame into a rotating frame, we apply a pseudo force i.e. centrifugal force radially outwards on the particle. Right? Also if a particle is having a circular motion in any frame of...

I saw a baseball pitching machine that throws baseballs at 40-70mph with one wheel... All that wheel does is rotate and as the ball touches the rotating wheel it accelerates and comes flying out of the machine at an appropriate angle.. My question is: what is the physics behind that wheel on...

How come we can rotate a molecule at many multiples of the angular momentum quantum (rotational degrees of freedom), but we can only rotate an electron at 2 different steps (spin degree of freedom)?

Situation: A uniform cylinder (Mass M, Radius R) is rotating down a slope of incline θ and distance s, there are two methods which I used to calculate the final speed, one of which considered forces acting on the cylinder and the other using energy, pure rolling assumed throughout, both give...

What I have: A hollow cylinder filled 1/3 its dia with slurry. Wt of cylinder is 987251 pounds Wt of slurry is 358157 pounds Radius of cylinder = 8.5 ft. RPM = 7.5 Time taken = 20 seconds What I need is : Torque required to roate the cylinder Torque required to rotate the slurry inside...

Okay I need to rotate a parabola on a cartesian coordinate system, y=x^2 by 90 degrees about the origin (either direction) without using piecewise, or inverse functions. Basically I am trying to use translations and deformations to accomplish this. Anyone thoughts?

Homework Statement A closed cylindrical canister with central axis coincident with the Z axis has a height H and a radius R. It is suspended by a rod coincident with the Y axis that passes through the canister, transecting its central axis at a height h above the bottom surface of the canister...

Hello everyone! A few days ago I was in my university I walked in my engineering building and I saw a HUDGE pendulum! Very big and so heavy! It was hung from the celling wall, not sure of its mass though... Anyhow! I was wondering why is it when we stabilize the mass of an object equally we...

Is the weight force an apparent force ? Sorry but on the web i can't find anything. For example if i should think about a man that is on a rotating plate,what are the apparent force ? I think surely the centrifugal force but should i consider even the wight force of the man ?

Homework Statement 1 A particle is gently placed on a frictionless rotating turntable at a distance r from the centre.Describe particle motion from both ground and table frame. 2 A particle is at a distance r from the centre of a frictionless stationary turntable.The turntable then starts...

Says Wikipedia: "The moment of inertia is a measure of an object's resistance to any change in its state of rotation". Now consider a rotating mass m that I would like to accelerate along its axis of rotation by a. Does this count as a "change in its state of motion"? Will it resist the...

Homework Statement We have an uniformly charged disk with total charge q, which is rotating around its axis with constant angular velocity w. Calculate electric and magnetic field in the axis and in the rotation plane. Calculate the radiated power in one cicle. Homework Equations...

Homework Statement Within the xy-plane, two vectors having lengths P and Q rotate around the z-axis with angular velocities ω and –ω. At t = 0,these vectors have orientations with respect to the x-axis specified by θ1 and θ2. How do I find the orientation of the major axis of the resulting...

Rotating Coupling Pin--Mechanical Failure as a Safety Precaution Hi everyone, I am RagingCalm, a mechanical design engineer. I hate to ask for help on my very first post but considering that I am utterly stumped and no one at the office can help me...well...ummm...help, please. :frown...

A 180 degree circular arc (i.e. a half sphere) is obvious: When you rotate this about its two end points, you get a sphere. What about for something less than 180 degrees (e.g. 90)?: I believe this forms an ellipsoid, with coefficients a and b being equal, with respect to...

Hello people, So i found out the tension in a ring rotating with constant angular velocity (in gravity free space) Considering a small element of mass dm - tension will provide the centripetal force, 2Tsin(dθ/2) = dmrω^2 sindθ ≈ dθ dm = m/2πr ds ds = rdθ T = (mrω^2)/2πNow, the other method...

Homework Statement A thin uniform rod is attached to an axis through its midpoint. The axis is standing on a disk rotating with constant angular speed \Omega about its symmetry axis. The rod's midpoint is located directly above the rotational axis of the disk. Let \theta denote the rod's...

Is shown like this in my book: Consider a rotating body with an angular acceleration α. There must be a tangential force component if it is rotating: For a general point on the body we can write: Ftan = mi * ai = mi * ri * α (1) Multiply by ri and sum up you...

Hi guys! I'm working some problems for our exam in a few weeks and there are a few problems we are unable to solve. One of them is: "A homogenous rod is free to rotate without friction around one of it's ends. Find the reaction force in function of the position of the rod." As you can see the...

I can't visualize spin... I know that its not just a particle rotating about its axis... Then how do I think of it?

I am simulating a rapidly rotating (horizontal axis, if that makes a difference) flywheel. The software isn't too sophisticated w.r.t. wind resistance, unfortunately, and seems to use the diameter of the rotating body as one of the main parameters, in addition to the velocity of the rotating...

In the case where you have a photonic clock bouncing a photon between 2 mirrors, if the mirrors are alligned on the vertical axis, bouncing the photon up and down and the overall clock traveling along the horizontal axis, then the whole thing makes sense to me. However, if you were to rotate the...

Homework Statement This is an answer to a problem involving rotating vectors I can't figure out what the blank spaces mean. Are there 0's there? Are there 1's? Help.

Homework Statement http://www.brookscole.com/math_d/special_features/stewart_shared/mathematica_labs/14-multipleintegrals/p05a.pdf Homework Equations The Attempt at a Solution My question concerns the (1) and (2) next to the figure of the rotating coordinate system...

Hi, So, I am learning about induced emf. I am having a hard time grasping the idea that we are interested in the angle between the normal to the plane of the coil and the magnetic field. In the standard illustration I actually understand it, but the following question confuses me. We are...

I understand that if we apply a force on the axis of rotation of a spinning disc, the torque is in a different direction, and the axis is moved in a direction perpendicular to the direction in which the force upon the axis was applied, determined by the right-hand rule. But what if the force...

In a uniformly rotating coordinate system the trajectories of freely moving objects are influenced by an apparent centrifugal and Coriolis force. Is there a coordinate system or metric (or both) in which these trajectories are geodesics instead?

In a brief history of time it says theft 'according to the uncertainty principle rotating black holes should emit particles'. However I do not understand why rotating black holes need to emit particles according to the uncertainty principle. I do understand why black holes emit particles it...

If a disc-like object was rotating so that its outside edge was at about 0.86c (causing a factor of change of about 2) relative to an observer, then would it contract in length along the axis of rotation, or the circumference (relative to the observer)? in other words, would it get thinner or...

Starting at BB everything moves outwards with linear momentum so unless the BB event was rotating where does the angular momentum come from, the Earth rotates, it orbits the sun, the galaxy is rotating and the sun orbiting within it. So it seems that angular momentum is the norm for bodies...

The direction of rotating bodies about a fixed axis. I am confused on how you should regard the the direction of mg sin x, the angular acceleration and the force exerted on the body by the axis, perpendicular to OG ( where O is the fixed axis location and G is the centre of mass of the body)...

-See attached diagram - A uniform disc of mass m and radius a is free to rotate in a vertical plane about a fixed smooth horizontal axis, the axis passes through the mp A of the radius of the disc. - It then asks you to dervie equations of motion for when AO makes an angle pheta with the...

A flywheel makes 80 radians in 4 second and is rotating with constant angular acceleration during this time . It makes 60 radians in next 4 second with constant angular velocity . Find initial angular velocity and the angular acceleration ? my answer is form this equation Q= w0t +...

1 ) If a body is rotating at uniform angular velocity then in t sec , the angular displacement is ... (complete ) my answer the angular displacement is increase . 2 ) If a body is making N revolutions in one second then its angular velocity in rad/sec is my answer the angular...

Find area of surface obtained by rotating the curve, URGENT? Using Simpson's rule n=10, find the area of the surface obtained by rotating the curve y=x+sqrt(x), 1 less than or equal to x less than or equal to 2, about the x-axis. Include at least five decimal places in your answer. Area = ...

Hi please I want from you check my answer http://store2.up-00.com/May12/Ueu86896.jpg http://store2.up-00.com/May12/fkl86896.jpg

Homework Statement A rectangular coil of 80 turns has an area of 0.01m^2. It rotates @ 3000rpm about one of its in plane axes, in a uniform magnetic field having B=1.5T. Calculate the rms voltage generated. Homework Equations 1 Tesla= 1 Weber/m^2. Change in flux of 1 Weber per second...

Hello, I have a question about force produced by rotating ball. Let's say the ball rotates clockwise. The rotating ball is attached to the rotation axis with a rigid rod. The rotating ball is placed inside of the box. The box is placed on the very sensitive scale. The box is vibrating...

This is very simple question, and i just need a 2nd opinion. We have a Space Station (preferably a torus) with angular velocity ω and radius r. We have a car inside which OPPOSES the angular velocity and moves with the speed ωr . So, will the gravity felt in this car be Zero? Or will it be...

Dear all, We can rotate the local coordinates of the element so that the stress tensor becomes diagonal. The new coordinate system would be the principal stress axes of which are in fact the eignevectors of the stress tensor. Once we have the eigenvectors ( which are generally orthogonal)...

We have met the idea that a radius of a circle rotating ANTI-CLOCKWISE can be used to draw a sine wave... I get that... it is a great idea but...why does it have to be rotating anti-clockwise. That seems so un natural to me. We were told it is a convention. Does that mean it is something...

I have a drum of radius of 1.375" with a wall thickness of .3025". It is rotating about its central axis at 2000 rpm. There are 6 holes drilled into the drum radially. I have a pin that slides in and out of those holes in order to release and stop the drum. I am trying to figure out the force of...

Hi, All: I know very little physics and/or materials engineering. I am just trying to see if there is something to the claim that alternating the usage of , say, backpacks/ shoes , will give an overall longer total life, i.e., if I will be able to get more useful days out of 2...

Hi I am wondering why a spinning cylinder will produce lift in an inviscid flow. From: http://www.grc.nasa.gov/WWW/k-12/airplane/cyl.html one of the mechanisms for lift generation was the sticking of fluid particles to the wall of the cylinder. I thought that the no slip condition only...