Angular acceleration Definition and 551 Threads

Homework Statement A disk is under constant angular acceleration \alpha. When it starts from rest it takes 10 revolutions before it reaches angular velocity \omega. How many additional revolutions does it take to accelerate the disk further to an angular velocity of 3\omega?The Attempt at a...

There is nothing to answer anymore. I have no time left for the project to use the data.

Homework Statement I have an angular acceleration question. I have two different scenarios I want to compare. The difference is the distance from rotational center point. The input torque is 1Nm in both scenarios. I want to accelerate a mass of 2kg over an 90 degree angle (0.5PI rad). My...

I am working on a project where i need to determine the angular acceleration from known linear acceleration. I have given it a try please let me know if its the correct approach. Linear acceleration = 70 G's (70x9.8 mts/sec2) Radius of cylinder = 0.203 mts Rotation of cylinder along center...

Hi guys, supposing there is a collar which can freely move along a rod. If the rod is rotating with a certain angular velocity, the rod will move away from the rotating point (it can never move towards the point). The acceleration of the collar has a radial component toward the point, hence the...

1. The problem statement, and my attempt at a solution is given in pic Please help me.

Homework Statement A string is wrapped several times around the rim of a small hoop with radius .08m and mass .18kg. The free end of the string is pulled upward in just the right way so that the hoop doesn't move vertically as the string unwinds. Find the angular acceleration of the hoop as...

Homework Statement The figure shows a view from above of two objects attached to the end of a rigid massless rod at rest on a frictionless table. Imagine a vertical rod, on the top end is a mass of m, an the bottom is a mass of 2m. The length of the rod is L and L/4 down from m (at top), a...

A grindstone in the shape of a solid disk with diameter 0.550 m and a mass of m = 50.0 kg is rotating at omega = 840 rev/min. You press an ax against the rim with a normal force of F = 160 N , and the grindstone comes to rest in 7.60 s. Find the coefficient of friction between the ax and the...

Homework Statement A wheel starts from rest and spins with a constant angular acceleration. As time goes on the accerlation vector for a point on the rim: a) decreases in magnitude and becomes more nearly tangent to the rim b) decreases in magnitude and becomes more nearly radial c)...

HI, I would appreciate if someone could provide me some suggestions. I am trying to figure out angular acceleration and angular velocity of opening a car hood. I think I have the sum of the torques correct however I am having a tough time with speed because the torque is not contant. I do...

Homework Statement Go to http://apcentral.collegeboard.com/apc/public/repository/ap08_physics_c_mech_frq.pdf Question two The solution is http://www.collegeboard.com/prod_downloads/ap/students/physics/ap08_physics_c_mech_sgs_rev.pdfThe Attempt at a Solution My question is part d) in the...

Homework Statement A flywheel rotates at a rate of 20 rpm. A motor provides a constant angular acceleration so that 30 s later it turns at a rate of 70 rpm. There’s a tiny splotch of paint on the flywheel, located 0.10 m from its center. During the acceleration period, what is the angular...

Homework Statement This is a two part problem, but I don't know what equation to use for part II. a) A record has an angular speed of 15.4 rev/min. What is its angular speed? Answer in units of rad/s. 1.61 rad/s b) Through what angle does it rotate in 1.1 s? Answer in units of rad...

Homework Statement A slope angled 36* to the horizontal has a hoop cylindrical shell going down it, which has radius 3cm and mass 100g. 1) Write down an equation of motion for the angular acceleration. 2) Will the linear acceleration change if the hoop is changed to a cylinder (i.e...

The blades in a blender rotate at a rate of 6100rpm. When the motor is turned off during operation, the blades slow to rest in 4.7s What is the angular acceleration as the blades slow down? f=6100rpm=366000rps dt=4.7s w=2(pi)f angular acceleration=dw/dt w=2(pi)3.66*10^5=2.3*10^6 rad/s...

We have to analyze this video: Givens: 1) An applied net torque due to the wind on the windmill is equal to 1500 N*m. 2) Each (of the 3) propeller props weighs approximately 45 Kg and has a Moment of Inertial equal to about 65% of that of a rod of the same mass being spun about its...

Homework Statement Problem definition - Conversion of torque from a pendulum to generate angular acceleration in a cylinder. Pendulum is fixed on one side and has adjustable mass on the other end. Length of the pendulum is constant. Homework Equations torque generated by pendulum =...

A ceiling fan consists of a small cylindrical disk with 5 thin rods coming from the center. The disk has mass md = 2.9 kg and radius R = 0.26 m. The rods each have mass mr = 1.4 kg and length L = 0.8 m. When the fan is turned on, it takes t = 3 s and a total of 15 revolutions to accelerate up...

Homework Statement The problem is as follows. A certain pulsar (a rapidly rotating neutron star) has a period of rotation of 0.033s, and this is observed to be increased at a rate of 1.26(10^(-5)) seconds per year. what is the value of the angular acceleration in rad/s^2? Homework...

Hello, I am in process of building a set up where i will be using a pendulum to impact a cylinder to generate angular acceleration. I started from basic physics for a answer and found the following method but doesn't seem to go any where from here. Please provide guidance. Torque = Moment...

Homework Statement A Yo-Yo is made up of twp solid disks each with radius R and mass M. The axle has radius r and is essentially massless. The Yo Yo is released to unwind. Find the angular acceleration of the YoYO as it falls in terms of r, R and g. Homework Equations \Sigma\tau=I\alpha...

Please see the attached figure.

To throw a discus, the thrower holds it with a fully outstretched arm. Starting from rest, he begins to turn with a constant anguLar acceleration. The diameter of the circle in which the discus moves is about 1.8 m. If a thrower takes 1.0 s to complete one revolution, starting from rest, what...

Hi all, first time posting so let's see how it goes! My problems are with a piece of physics coursework I'm doing for my A-level courses. I chose to investigate the 'torque effect' on single propeller planes. (If you are unsure of what this is, its basically Newtons third law, reasoning that...

Hi there I need some help in calculating the force created by angular motion. I am designing a wheelie bar for my motorcycle and need to know what force the design must be able to handle. I have attached a simple sketch of the design. Taking into account; torque produced by the engine...

Homework Statement A 26.0 in diameter wheel is rotation initially at 210.0 revolutions per minute. It slows down uniformly and comes to rest in 15.0 seconds. a.) what is the angular acceleration? b.) through how many revolutions did it turn in those 15.0s? Homework Equations...

Homework Statement How do I solve for linear acceleration or angular acceleration without one or the other? I am given the mass of the object (a yoyo), the inner radius, the outer radius, and Icm (moment of inertia at the center of mass). Attached in a picture of the problem...

The blades in a blender rotate at a rate of 7000 rpm. When the motor is turned off during operation, the blades slow to rest in 3.4 s. What is the angular acceleration as the blades slow down? Lets first convert rpm to rps and then multiply by 2π to get its angular velocity. 7000rpm *...

Homework Statement A bar on a hinge starts from rest and rotates with \alpha=(10+6t) rad/s2 t is in seconds. Determine the angle in radians the bar turns in the first 4 seconds. Homework Equations I'm a little stumped how to get this one started. I assume i need to get it from angular...

Homework Statement A uniform rod of length 0.750 m and mass 1.20 kg is pivoted at one end by a smooth pin as shown below. The rod is released from the vertical position and given a slight nudge to release it from the vertical position of unstable equilibrium...

Homework Statement The goal is to solve for angular acceleration with the end variables being m1,m2,m3, R, r, g. M2 > M1. An atwood machine is a pulley with 2 masses, one on each side. Homework Equations Tnet = I * angular acceleration Fnet = ma The Attempt at a Solution I know...

Homework Statement A uniform rigid rod with mass Mr = 5.9 kg, length L = 2.9 m rotates in the vertical xy plane about a frictionless pivot through its center. Two point-like particles m1 and m2, with masses m1 = 5.7 kg and m2 = 1.8 kg, are attached at the ends of the rod. What is the...

Homework Statement A wheel rotating about a fixed axis has an angular position given by theta= 3.0 - 2.0t^3, where theta is measured in radians and t in seconds. What is the angular acceleration of the wheel at t = 2.0s?Homework Equations wf = w + atThe Attempt at a Solution I realize I most...

A rotating wheel requires 4.7 s to rotate through 33.5 rev. Its angular speed at the end of the 4.7 s interval is 45.5 rad/s. What is its constant angular acceleration? Assume the angular acceleration has the same sign as the angular velocity. Answer in units of rad/s2...

Homework Statement A 70cm diameter wheels accelerates uniformly from 160 rpm to 280 rpm in 4.00s. Determine: a) it's angular acceleration, and b) the radial and tangential components of the linear acceleration of a point on the edge of the wheel 2.00s after it has started accelerating...

Homework Statement Dario, a prep cook at an Italian restaurant, spins a salad spinner 20.0 times in 5.00 seconds and then stops spinning it. The salad spinner rotates 6.00 more times before it comes to rest. Assume that the spinner slows down with constant angular acceleration. a) Find the...

Homework Statement As a result of friction, the angular speed of a wheel changes with time according to dθ/dt=ω0*e^-σt , where ω0 and σ are constants. The angular speed changes from an initial angular speed of 3.96 rad/s to 3.46 rad/s in 3.92 s . Determine the magnitude of the angular...

Homework Statement The blades of a kitchen blender rotate counterclockwise at 2.2×10^4 rpm (revolutions per minute) at top speed. It takes the blender 2.1 seconds to reach this top speed after being turned on. What is the average angular acceleration of the blades? Homework Equations...

Homework Statement A rock is wedged into the treads of a 15 in radius tire. The car to which it is attached is driving down the road at 70mph. What’s the angular acceleration of the rock? Homework Equations ar=- \omega02r The Attempt at a Solution Not sure where to begin...

Homework Statement A high-speed drill rotating ccw at 2200rpm comes to a halt in 2.80 s. What is the drill's angular acceleration? Homework Equations (where w = angular velocity) w = 2╥/T v = wr a = v^2/r a = w^2*r The Attempt at a Solution I start by calculating w. So first I took it to...

Homework Statement I have a motor, with an armature that has a mass of 250kg , and a diameter of 30 cm. Assuming the mass of the armature is evenly distributed, the rotational inertia of the armature is 22.5 kg-m^2. Now the motor accelerating unloaded, with armature current regulated so that...

Homework Statement An electric motor starts from rest at time t=0. Its angular velocity is: w=100t-4t3 A) If the angle of rotation, x, of the motor is also zero when t=o, determine an expression for this angle in terms of t. B) Determine the angular velocity when x=2pi radians. Give your...

1. The problem: A Force F is provided at the top of a rod placed vertically placed on a smooth frictionless surface. The length of the rod is L and its mass, M. Find the angular acceleration of the rod at the instant the force is applied. - Please tell me how to solve this and why you...

Ok, so... \tau = \frac{dL}{dt} and L\equiv I\omega so \tau = \dot{I}\omega + I\dot{\omega} = \dot{I}\omega + I\alpha and i don't believe it'd be wrong to write (shouldn't be...right?) \alpha = \frac{\tau-\dot{I}\omega}{I} --- the situation I'm looking at is that of a disc (of radius 'R')...

I always thought that torque = I*d²θ/dt² so that, if there is any d²θ/dt² on an object with a moment of inertia (both with respect to the same point)..then there must be a torque applied. However, I've found a case where this isn't true. So, I'm assuming there is more to it then that...

Homework Statement A wooden door is closed by applying a perpendicular force to it. If the magnitude of the force is constant and takes 2 seconds for the door to close, how long would it take to close the door with the same amount of force, in the same manner, if the door was made of a...

Homework Statement A certain wheel has a rotational inertia of 12 kg m2. As it turns through 5.0 rev its angular velocity increases from 5.0 rad/s to 6.0 rad/s. If the net torque is constant, its value is: Homework Equations Angular acceleration = dW/dT Net torque = (angular...

Homework Statement A rotating wheel requires 3.00 s to rotate 232.5 rads. It's angular velocity at the end of the 3.00 s interval is 98 rad/s. whatis the constant angular acceleration of the wheel? Homework Equations Not sure The Attempt at a Solution Is this question more complex...

Homework Statement A motor car with wheels of 0.6,m diameter accelerates uniformly from 3 to 18m/s in 10 seconds. Find: a) the angular acceleration of the wheels b) the number of revolutions made by each wheel during the speed change Homework Equations A=v-u/t (angular equivilent with...