Angular velocity Definition and 841 Threads

Homework Statement A mass m1 with speed v1i colides with a mass m2 of length 1m, initially at rest, and gets stuck with it. (a) Express the angular velocity in functon of v1i. (m=m1=m2) Homework Equations w=v/r The Attempt at a Solution Since the collision is totally...

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...

Homework Statement Two people are on a ride where the inside cars rotate at constant angular velocity three times the constant angular velocity of the outer cars. If the two cars are in line at t = 0, and moving at 3ω and ω respectively, at what time will they next pass each other? The...

Question: The flat circular disc rotates about a vertical axis through O with a constant angular velocity of 240rpm. Prior to rotation, each of the 0.5kg sliding blocks has the position x=25mm with no force in its attached spring. Each spring has a stiffness of 400N/m, Neglect any friction...

Homework Statement The flat circular disc rotates about a vertical axis through O with a constant angular velocity of 240rpm. Prior to rotation, each of the 0.5kg sliding blocks has the position x=25mm with no force in its attached spring. Each spring has a stiffness of 400N/m, Neglect any...

Hello, I need some help verifying whether what I did is correct. Homework Statement Attached is a screenshot of the problem. Homework Equations Angular momentum L = \vec{r} × m\vec{v} = mvr \sin{\theta} Conservation of angular momentum. The Attempt at a Solution This is my...

Suppose a rigid body (say a sphere) ofis rotating with angular velocity A. Any point at a distance r from the axis of rotation has tangential velocity v=A*r and that v must be less than c. Does this mean that : 1. The rigid body can only be a certain maximum (radial) size r, where r<A/c? 2...

How do you prove that angular velocity is just the time derivative of each Euler angle times the basis vector of its respective frame? I remember it used to be perfectly clear to me a while back, but now I don't remember how the result was derived, and I couldn't find it in any of my books I...

Homework Statement A ring (mass 2 M, radius 1 R) rotates in a CCW direction with an initial angular speed 1 ω. A disk (mass 2 M, radius 2 R) rotates in a CW direction with initial angular speed 4 ω. The ring and disk "collide" and eventually rotate together. Assume that positive angular...

Homework Statement This is a question from the physics textbook Don't Panic Volume I, chapter XIV. A man, mass M, stands on a massless rod which is free to rotate about its center in the horizontal plane. The man has a gun (massless) with one bullet, mass m. He shoots the bullet with...

Homework Statement Calculate the angular acceleration and angular velocity of a 4 kg object rotating in a circle of 3 m radius in a time of 6 s. Homework Equations Angular acceleration = ω2*r Angular velocity= angular displacement/time ? The Attempt at a Solution Really...

Homework Statement The instantaneous configuration of a slider crank mechanism has a crank GH 10cm long, the connecting rod HP is 50cm. The crank makes an angle of 60 degree with the inner dead centre position and is rotating at 110 rev/min. Determine the velocity of the piston P and the...

Homework Statement A fair ground ride comprises of a car, connected to an arm, secured to the main driver by a pin. It rotates about a vertical axis. when operational: a) what type of stress is experienced by the pin?, and what type of stress is experienced by the arm? b) if the max allowable...

Homework Statement The instantaneous configuration of a slider crank mechanism has a crank GH 10cm long, the connecting rod HP is 50cm. The crank makes an angle of 60 degree with the inner dead centre position and is rotating at 110 rev/min. Determine the velocity of the piston P and the...

hi i have two different systems (i have tried to upload them but they both exceed the size of the upload limit). One is a dc motor block diagram (it has a PID at its controller) the other is a bldc motor model with a PID controller input. The block diagram of the DC motor consists of an armature...

Homework Statement A grinding wheel is a uniform cylinder with a radius of 8.70 cm and a mass of 0.400 kg. a)calculate the moment of inertia about the center. b)Calculate the applied torque needed to accelerate it from rest to 1950 rpm in 6.00 s if it is known to slow down from 1250 rpm to...

Homework Statement A uniform thin rod of length L=2.2 m and mass 5 kg can rotate in a horizontal plane about a vertical axis through its center. The rod is at rest when a 0.2 kg ball of putty, moving in the horizontal plane of the rod, hits and sticks to one end. As viewed from above, the...

Homework Statement How fast (in rpm) must a centrifuge rotate if a particle 7.0 cm from the axis of rotation is to experience an acceleration of 1.2×10^5 g's? The Attempt at a Solution well first i made 7 cm .07 m. then i changed acceleration to 1.18x10^6 m/s^2 by multiplying 1.2x10^5 g's...

Homework Statement A person of mass 71 kg stands at the center of a rotating merry-go-round platform of radius 3.2 m and moment of inertia 920 kg * m^2 . The platform rotates without friction with angular /velocity 1.7 rad./s. The person walks radially to the edge of the platform. Homework...

Homework Statement Part a: A newly discovered planet has a mean radius of 4030 km. A vehicle on the planet's surface is moving in the same direction as the planet's rotation, and its speedometer reads 169 km/h. If the angular velocity of the vehicle about the planet's center is 5.28 times as...

Homework Statement Calculate the angular acceleration and angular velocity of a 4 kg object rotating in a circle of 3 m radius in a time of 6 s. Homework Equations The Attempt at a Solution Angular acceleration = ω2*r C=2∏r= 2*3.14*3=18.84 360°/57.3°=6.28 rad/s 6.28/6=...

If i have a shaft & I'm applying a driving torque D at one end & at other end there is resisting torque R due to bearing friction, etc. Then if D>R, i have net torque = moment of inertia times angular acceleration. Since the ang. accln is constant with respect to time, will the ang. speed of...

Homework Statement A solid disk of radius 5m and mass 8 kg rotates clockwise at 1.5 rad/s. Above this disk is a hoop of radius 2.5 m and mass 8 kg , rotating counterclockwise at 3 rad/s. The hoop drops down onto the disk, and friction causes them to rotate together. Find the final velocity...

I am attempting to find the angular velocity of a 3D box that is balanced on one of its corners and allowed to fall under the force of gravity alone at the instant the box impacts. Take the simplest case for example where the box is square on all sides and falls in a way that results in one of...

Problem: Calculate spin angular momentum of Jupiter Relevant Equations: L = Iω I = (2/5)*M*r2 (for a uniform sphere) ω = (G*M/r3)1/2 (I calculated this earlier in the homework, but I've looked it up and I think it's right) Attempt at a Solution: I thought this should be pretty...

Homework Statement An electric dipole consists of 2.0 g spheres charged to 5.0 nC (positive and negative) at the ends of a 12 cm long massless rod. The dipole rotates on a frictionless pivot at its center. The dipole is held perpendicular to a uniform electric field with field strength...

Homework Statement Rigid body is rotating with 3 radians per second about an axis parallel to ax - 2ay + 2az. Express this mathematically. Homework Equations ax - 2ay + 2az The Attempt at a Solution w(vector)=w(1,-2,2) / 3 = (1,-2,2) I need confirmation if this is correct or not...

Homework Statement A mass attached to a spring which is mounted on a turntable. If you wanted to double the angular velocity, but keep the radius of the circle the same, by how much would you change the spring constant? Homework Equations \omega = \frac{v}{r} The Attempt at...

So I've been working on understanding precession better. I had a whole other thread where it was explained to me how a torque applied to an object with angular momentum can result in precession. But this is sort of a different question, so I'd like to start a new thread for it. In my physics...

Homework Statement Consider a rigid sphere of radius 1 and center at (0,0,0) that rotates about its center. The angular velocity is $\omega(t) = (\cos(t) , \sin(t), \sqrt(3))$. Does the path of the point starting at (0,0,1) ever reach this point at a later time? Homework Equations...

Homework Statement I am approximating an object as a cylinder (h=6, r=1, mass=200lb). The cylinder is in the process of toppling over from a vertical position. I will assume that the cylinder can pivot freely on the bottom surface. At some angle theta, the cylinder will strike an object...

Can someone tell me what is the best angular velocity to be exerted on the door for it to close automatically if I were to design a door with spring hinges.

Hope you can offer me some help with this question - I feel close to getting it myself but have spent ages looking at it now. Question and working so far is attached. I think what I need to do to enable me to perform the integral is to get theta as a function of time, or instead somehow...

What it the maximum angular velocity that can possibly be attained by a rigid body?

Homework Statement A large turnable shaped like a wooden board with sizes A and B and mass M rotates. A drop of water with mass m drops on 80cm from the axis of rotation. Find the final angular velocity of the system if the initial angular speed is ω. Homework Equations I know how to...

Homework Statement Link AB has angular velocity and angular acceleration as shown. Determine the velocity and acceleration of point C and the angular acceleration of link BC at this instant. Express them as Cartesian vectors. https://www.physicsforums.com/attachments/41853 Homework Equations...

Homework Statement A uniform cylinder of radius 12 cm and mass 25 kg is mounted so as to rotate freely about a horizontal axis that is parallel to and 6.6 cm from the central longitudinal axis of the cylinder. If the cylinder is released from rest with its central longitudinal axis at the...

Homework Statement Calculate the angular acceleration and angular velocity of a 2kg object rotating in a circle of 1.5m radius in a time of 3s. Homework Equations w=v/r 2*pie*r The Attempt at a Solution Hi all, every attempt so far has been a failure, I just can't work out...

Homework Statement A ball of mass 0.5 kg is attached to the end of a string of length 0.5 m. The ball rotates in a horizontal circular path about a vertical axis. The maximum tension on the string cannot exceed 324 N. What is the maximum possible angular velocity of the ball in rad/s ...

Homework Statement An early method of measuring the speed of light makes use of a rotating slotted wheel. A beam of light passes through a slot at the outside edge of the wheel, as in Fig. 10-29, travels to a distant mirror, and returns to the wheel just in time to pass through the next slot...

A centrifuge is used to increase the sedimentation rate of particles suspended in a liquid, over the rate produced by gravity alone. Find the angular velocity of a centri - fuge in which a particle 10.0 cm from the axis of rotation experiences a radial acceleration of 1.00*  10^3 times...

Homework Statement An aircraft passes directly over you with a speed of 900 km/h at an altitude of 10,000 m. What is the angular velocity of the aircraft (relative to you) when directly overhead? Three minutes later?Homework Equations Where were studying center of mass and Moment of inertia...

Homework Statement Here's the question: Imagine that you are a gymnast on a high bar, 180 degrees from the right horizontal in a fully extended position (NO angular velocity at this point). Assuming that the center of mass of your body is 1.288m from your extended hands, and that your radius...

Homework Statement An homogeneous rod is fixed to an extremity and is rotating around a vertical axis, doing an angle of theta with the vertical. (in the scheme I made I wrote alpha but it's theta! (θ)) If the length of the rod is L, show that the angular velocity needed to make it turn...

Homework Statement Derive the expressions for the i_r and i_θ components of velocity and acceleration. Homework Equations r=|r|i_r \omega=\frac{dr}{dt} \alpha=\frac{dω}{dt}=\frac{d^2r}{dt} The Attempt at a Solution r=|r|i_r \omega=\frac{dr}{dt}i_r+r\frac{di_r}{dt}...

A rigid "H" falls rotating about one of its legs. What's its angular velocity? A rigid body is made of three identical thin rods, each with length L = 0.340 m, fastened together in the form of a letter H, as suggested by the figure here. The body is free to rotate about a horizontal axis that...

Dear All, After long time, I have to start working again on basic physics for my application in one of our automotive project. Anyway, my problem is, I receive the angular velocity of wheel from external source like (say CAN bus) for every 10ms, now, I need to calculate the Angular position...

Homework Statement Use Newton's 2nd Law, sum of torques, and kinematic equations to determine the angular speed of the spool shown in the figure below. Assume the string has a negligible mass, and it turns without slipping. Use g=10 m/s2 for acceleration due to gravity. Homework...

Say I have an odd shaped rigid body in pure rotation. I fix an orthogonal x-y-z coordinate system to the body, and coincide the origin of this coordinate system to the origin of my global coordinate system X-Y-Z. I have 3 Eulerian angles (as functions of time) which I can use to describe the...

Homework Statement A solid disk with a radius of 1.4cm is a rest. The disk has 2.0m of string wound on to its circumference. The string is pulled off the disk by a constant force in a time of 7.3s. What is the final angular velocity of this disk? Homework Equations v = r*ω The...