Angular velocity Definition and 866 Threads

Homework Statement A rotating beacon is located 1 kilometer off a straight shoreline (see figure). If the beacon rotates at a rate of 3 revolutions per minute, how fast (in kilometers per hour) does the beam of light appear to be moving to a viewer who is 1/2 kilometer down the shoreline...

Homework Statement A discus thrower ( with arm length of 1.2 m) starts from rest and begins to rotate counterclockwise with a constant angular acceleration of 2.5 [rad/s^2]. What is the magnitude of the total acceleration of the discus when its angular velocity is 9.0[rad/s]? Homework...

Homework Statement A mass m1= 0.200 kg is tied to a string with enough slack to swing around someone's head with a radius of 0.500 meters. What angular velocity must m1 have in order to hold up a mass m2 hanging from the other end of the string if m2 is 0.300 kg?Homework Equations ac= v^2/r...

Homework Statement A 2.0-m measuring stick of mass 0.175 kg is resting on a table. A mass of 0.500 kg is attached to the stick at a distance of 74.0 cm from the center. Both the stick and the table surface are frictionless. The stick rotates with an angular speed of 5.30 rad/s. (a) If the...

Good morning, I have an iron bar (35 cm long) hinged on an axis. The path of this bar is limited to 45 degrees. I have to measure the angular velocity of the bar when it rotates 45 degrees. I need to get a graph of variation of the angular velocity along the 45 degree paths. The time taken to...

Homework Statement A 1.15-kg grinding wheel 22.0 cm in diameter is spinning counterclockwise at a rate of 20.0 revolutions per second. When the power to the grinder is turned off, the grinding wheel slows with constant angular acceleration and takes 80.0 s to come to a rest. (a) What was the...

Hi all, please help me here! Im confused, is direction of angular velocity perpendicular to the plane of motion, or along the plane of motion?? From hyperphysics - http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html -...

Just curious, explanation if youre going to answer please! 2 horizontal disks stacked on one another spinning at constant v, (about a frictionless axis perpendicular to their center), both have mass. Okay, so let's say its possible to instantaneously remove the top disk. So would that make...

Hello, i have some problems with the ergosphere of a rotating black hole. I can show that an object must rotate with the black hole and a can determine the intervall of possible velocitys. But is it possible to calculate the exact velocity? How it depends on the initial velocity of the...

I was going through Periodic Motion chapter of my book and came across an equation while defining the relation between Time Period of on oscillating particle and force constant. k/m=w2 which was applied in, T = 2xpie/angular velocity can anyone please help me define this equation. I can't seem...

Homework Statement [/B] A spherical satellite of approximately uniform density with radius 5.1 m and mass 280 kg is originally moving with velocity 2600, 0, 0 m/s, and is originally rotating with an angular speed 2 rad/s, in the direction shown in the diagram. A small piece of space junk of...

I have the "robotic arm" shown in figure...the angular speeds w1, theta, w3 are given...they are asking me to find the total angular velocity of the disk. Can anyone explain me (conceptually) 1) what do we mean by total angular velocity of the disk and 2) how to find it...i have not understood...

Hello! :) When solving a problem, I had to calculate the angular velocity of a homogenius rod when it comes to vertical position, after being released from a horisontal position (the rod is fixed at one end). This is as usually done with energy conservation, using the rotational energy of the...

Homework Statement 1. It has been argued that power plants should make use of off-peak hours (such as late at night) to generate mechanical energy and store it until it is needed during peak load times, such as the middle of the day. One suggestion has been to store the energy in large...

Homework Statement Starting from rest, a spinning compact disk undergoes an angular acceleration of 5.0 rad/s^2. What is the angular speed of the disk after 3 revolutions? Homework Equations a=Δω/Δt ω=Δθ/Δt The Attempt at a Solution I do not understand how to solve this equation when I am not...

I am doing an analysis concerning the torque-free motion of an axisymmetric body (J1 = J2 != J3). The angular velocity is given \omega(t) = [\omega_t\ sin(\Omega t), \omega_t\ cos(\Omega t), \omega_{z0}] where \omega_t, \Omega and \omega_{z0} are constants. I would like to determine the...

On exactly what factors does the rotational angular velocity of a planet depend ? Can a mathematical expression be derived for it ?

Homework Statement Hi all I am doing a school physics project and I am trying to find the maximum angular velocity of a DC motor. I have built a circuit consisting of a charged capacitor (of known voltage) and a motor. I then try to predict the maximum angular velocity attained by the motor...

Homework Statement angular velocity about the axle = 65 rads^-1 diameter = 0.54m radius= 0.27m 1/2radius= 0.135m[/B]Homework Equations v=rw w=θ/t a=v^2/r=w^2r (Might be the probability that i have to use another equation)[/B]The Attempt at a Solution Firstly i cut the diameter in half which...

Two hollow spheres, both the mass and radius R M , which are rotating around a center of mass ( CM ) , with an initial period To, are kept distant from each other by an ideal wire with a distance of 8R. At a given instant a motor is driven by wrapping the wire and making the two spheres meet...

Homework Statement a motor traveling at a constant speed is just able to completely go round a vertical circular track of radius 8m The total mass of motor is 210kg i)Compute the angular velocity at the top of the track ii)compute the maximum force on the track Homework EquationsThe Attempt...

Homework Statement A small circular block of mass M traveling with a speed v on a frictionless table collides and sticks to the end of a thin rod of with length D and mass M. The picture shows a top down view of the block and rod on the frictionless table. What is the rod's angular velocity...

Hello! I was looking to find out about an equation that would tell you the maximum angular velocity an electric motor can put out in terms of the geometry of the motor (area of the rotating coil, number of turns, etc), the EMF applied to the coil, magnetic field surrounding the coil, and so on...

Hello! This isn't a homework question, and I don't think it is too homework-like, but if I'm mistaken I apologize. My question is if you had a battery, or some source of electrical energy, hooked up to a coil of wire in a constant magnetic field, in such a way that the wire spins around...

Homework Statement I have a physical pendulum made of a leg which mass is ignored, with a length of 1m, two objects of mass are placed on the bottom and the top of the leg, the first with a mass of m1= m1, and the second with a mass of m2= 3m1, both are L/2 away from the pivot point. It's...

Homework Statement In the figure, block 1 has mass m1 = 450 g, block 2 has mass m2 = 530 g, and the pulley is on a frictionless horizontal axle and has radius R = 5.3 cm. When released from rest, block 2 falls 71 cm in 5.0 s without the cord slipping on the pulley. (a) What is the magnitude of...

one thing every one says that our (any) galaxy is hundreds and thousands of lightyear long and also they rotate about their center then if they rotate with very low angular velocity then also the velocity of the extreme will cross the light speed? will it just think nd reply... (v=ω X r)

Hello everyone. I'm new here, though I've been using the site for a long time now. Now, I have a question. =) Suppose I have a vehicle with 3 wheels, one frontal passive wheel, and two wheels with different motors in the back. How will I go about calculating the angular velocity of the car, if...

Hi guys, My first time here. Looks like a nice forum with friendly members. I have a question. I'm kinda confused by this (and I know it's a shame since I'm on my third year University, almost making my degree). What I remember from my kinematics/dynamics classes this (or similar) equation...

Homework Statement The angle of a pendulum is θ(t)=(0.270rad)cos(4.00t+1.00π), where t is in seconds. Determine the initial angular velocity. Homework Equations ω=2πf The Attempt at a Solution [/B] I solved for the frequency, which was 6.37E-1 Hz and subbed it into the formula above and...

Homework Statement A gyroscope takes 3.8 s to precess 1.0 revolution about a vertical axis. Two minutes later, it takes only 1.9 s to precess 1.0 revolution. No one has touched the gyroscope. Explain Homework Equations ω = Δθ/Δt ω = ωo + at The Attempt at a Solution So is the gyroscope...

Homework Statement Solve: A*sin(ωt + Θ) = L*i''(t) + R*i'(t) + (1/C)*i(t). Where: A=2, L = 1, R=4, 1/C = 3 and Θ=45°. Homework Equations The system has to be solved by i(t) = ih + ip. I gave the values to A, L, R, 1/C and Θ. I can also give values to ω, but I've come to a doubt when solving...

Hello buddies, Could someone please help me to understand where the second and the third equalities came from? Thanks,

Hello, I'm looking to try to use a gyroscope to determine the rocking motion (just side to side - not back and forth) of a boat while it is traveling forward or sitting still in the water. Specifically, I'm looking for the boat's angle from vertical and this angle's velocity. Can I do this...

Homework Statement A child (mc = 36 kg) is playing on a merry-go-round (mm = 225 kg, R = 2.9m) that is initially at rest. The child then jumps off in a direction tangent to the edge of the merry-go-round. The child has a speed of 5.0 m/s just before she lands on the ground. What is the...

Homework Statement A solid sphere of mass m and radius a can rotate freely about a point A on its surface. The sphere is held initially at rest with the line OA through A and the centre of the sphere O horizontal and is released under gravity. Find the angular velocity of the system when OA...

Homework Statement A bicycle rider is moving with a velocity of 13.0 m/s. What is the angular velocity of his wheels if they have a diameter of 0.660m? Assume the wheels are rolling without slipping. a) 39.4 m/s b) 19.7 m/s c) 39.4 s-1 d) 4.29 s-1 e) none of the above Homework Equations v =...

Homework Statement Finding angular velocity after impact Homework Equations Moment of inertia x angular velocity = constant The Attempt at a Solution Hi, I believe that angular momentum is conserved in this case? If that's the case, how do I use the formula to calculate angular velocity if...

Homework Statement In a charming 19th-century hotel, an old-style elevator is connected to a counterweight by a cable that passes over a rotating disk 3.50m in diameter (the figure (Figure 1) ). The elevator is raised and lowered by turning the disk, and the cable does not slip on the rim of...

Homework Statement A star with mass 2.4x1030 kg and diameter 1.7x109 m rotates once every 34 Earth days. It eventually dies and becomes a white dwarf, shedding about half of its mass and contracting to a diameter of 1.9x108 m. If we approximate the star as a perfect sphere, what is its...

Homework Statement See the attached image. Homework Equations ##T = 1/2 \omega^2 I## The Attempt at a Solution So ##I_1,I_2,I_3## are just the moments of inertia of the object with regards to the 3 axes. Right? OK, then I intuitively assume that the total kinetic energy must simply be...

Homework Statement Homework EquationsThe Attempt at a Solution the displacement should be the area under the line , it was traveling backwards for 3 seconds, then it would take an additional 3 seconds to get back to the starting position. From there, the wheel rotates forward for 4 more...

I'm planning on carrying out an investigation with a golf ball and projectiles. Is there any type of equipment/sensor that I can used to measure the rotational speed/angular velocity? I know a gun chronograph can be used to detect the velocity but what can I used to detect the angular velocity...

Homework Statement Force represented by F(t)=20+t+5t^2 [N] acts upon the rim of a disk. How much time has to pass before the disk has angular velocity of 200 revs\sec? R and I are known. Homework Equations \begin{equation*} \tau=I\alpha \end{equation*} \begin{equation*} \tau=R \times F...

Suppose that a bicyclist is moving in a circle of radius R, leaning inwards at an angle a from the verticle, and that the height of the person (h) is less than R but not negligible. I am trying to find the angular velocity the bicyclist must move at. I tried doing this in two ways: using...

A 2.3kg , 20-cm-diameter turntable rotates at 100 rpm on frictionless bearings. Two 500g blocks fall from above, hit the turntable simultaneously at opposite ends of a diagonal, and stick. What is the turntable's angular velocity, in rpm, just after this event?I first cacluted the angular...

Hello, I need to find the angular velocity using Schwarzschild metric. At first I wrote the metric in general form and omitted the co-latitude: ds2=T*dt2+R*dr2+Φ*dφ2 and wrote a Lagrangian over t variable: L = √(T+R*(dr/dt)2+Φ*(dφ/dt)2) now I can use the Euler–Lagrange equations for φ...

Homework Statement I'm doing a coursework where I must find the angular acceleration of a rolling tin can using theoretical values. I have its mass and radius. I actually have experimental data so i have access to the actual values of angular velocity and angular acceleration, as well as time...

Homework Statement Hey so I've made a motor that looks and works exactly like the one in this video The assignment is asking me how I would go about finding the angular velocity, specifically " Analysis of the energy changes involved in the motor to work out the speed/ or angular velocity"...

Homework Statement A circular space hotel in orbit around the Earth has a radius of 220m. in order to produce "fake gravity" along the outer rim, it is desired to rotate at a speed that will produce a centripetal acceleration of 9.81 m/s^2. A) find the tangential speed of appoint on the rim...