What is Angular acceleration: Definition and 567 Discussions
In physics, angular acceleration refers to the time rate of change of angular velocity. As there are two types of angular velocity, namely spin angular velocity and orbital angular velocity, there are naturally also two types of angular acceleration, called spin angular acceleration and orbital angular acceleration respectively. Spin angular acceleration refers to the angular acceleration of a rigid body about its centre of rotation, and orbital angular acceleration refers to the angular acceleration of a point particle about a fixed origin.
Angular acceleration is measured in units of angle per unit time squared (which in SI units is radians per second squared), and is usually represented by the symbol alpha (α). In two dimensions, angular acceleration is a pseudoscalar whose sign is taken to be positive if the angular speed increases counterclockwise or decreases clockwise, and is taken to be negative if the angular speed increases clockwise or decreases counterclockwise. In three dimensions, angular acceleration is a pseudovector.For rigid bodies, angular acceleration must be caused by a net external torque. However, this is not so for non-rigid bodies: For example, a figure skater can speed up her rotation (thereby obtaining an angular acceleration) simply by contracting her arms and legs inwards, which involves no external torque.
Homework Statement
An Atwood's machine consists of two masses, m1 and m2, which are connected by a massless inelastic cord that passes over a pulley, Fig. 10-70. If the pulley has radius R and moment of inertia I about its axle, determine the acceleration of the masses m1 and m2 (a), and...
Hi, i would be grateful if anyone could help me find out the angular acceleration and angular velocity of a flywheel?
The flywheel is made from solid steel 500mm diamter x 78mm thick and is supported by two free running bearings (frictionless). The flywheel is rigidly attached to a 30mm...
Homework Statement
A tire 2.00 feet in diameter is placed on a balancing machine, where it is spun so that its tread is moving at a constant speed of 60.0 mi/h. A small stone is stuck in the tread of the tire. What is the acceleration of the stone as the tire is being balanced?
Homework...
Here are three questions on my physics homework and my attempts to solve them...am I looking at this the right way?
Question 1: A tire placed on a balancing machine in a service station starts from rest and turns through 4.7 revolutions in 1.2 seconds before reaching it's final angular speed...
Uniform Angular Acceleration please help :)
A wheel is subjected to uniform angular acceleration. Initially its angular velocity is zero. During the first 1-s time interval, it rotates through an angle of 88.3
Through what angle does it rotate during the next 1-s time interval? - I found the...
Homework Statement
During normal operation, a computer's hard disk spins at 5400 rpm. If it takes the hard disk 8.4 s to reach this angular velocity starting from rest, what is the average angular acceleration of the hard disk in rad/s2?
Homework Equations
?
The Attempt at a...
Homework Statement
A wheel is subjected to uniform angular acceleration. Initially its angular velocity is zero. During the first 1-s time interval, it rotates through an angle of 90.6degrees.
(a) Through what angle does it rotate during the next 1-s time interval?(in degrees)
(b)...
Angular Acceleration (please help)
A cyclist starts from rest and pedals so that the wheels make 7.5 revolutions in the first 4.8 seconds. What is the angular acceleration of the wheels (assumed constant)?
I have coached and taught baseball collegiately and professionally for the past 15 years and have stumbled upon a question that is beyond my math education.
How does linear movement of a rotating system effect the angular acceleration of that system if the system is moving left to right and...
[SOLVED] angular acceleration, displacement
Homework Statement
A flea is at point A on a horizontal turntable 9.3 cm from the center. Place the coordinate origin at the center of the turntable withthe positive x-axis fixed in space and initially passing through A. THe turntable is rotating at...
Homework Statement
Imagine a car driving on the XY plane in the +y-direction. If it is slowing down, in what direction is the angular acceleration of the wheels?
(a) the +x-direction
(b) the -x-direction
(c) the +y-direction
(d) the -y-direction
(e) the +z-direction
Homework Equations...
1. The tub of a washer goes into its spin-dry cycle, starting from rest and reaching an angular speed of 2.2 revolutions/s in 8.4 seconds. at this point the person doing the laundry opens the lid, and a safety switch turns off the washer, the tub slows to rest in 9.5 seconds.
through how many...
[SOLVED] Angular acceleration of disk
For the system below, determine the tension in each rope, the linear acceleration of each mass and the angular acceleration of the disk. \ g=10 m/s^2. Use \ I=4 kgm^2.
So far I have drawn the free-body diagram for m1 and m2
\ 120 - T_1 = 12a_1 and \...
A 5.0 kg, 60-cm-diameter disk rotates on an axle passing through one edge. The axle is parallel to the floor. The cylinder is held with the center of mass at the same height as the axle, then released.
What is the cylinder's initial angular acceleration?
ok so this is what i think i...
Homework Statement
A collar at point B slides on a 4 kg uniform rod CD. Knowing that in the position shown, crank AB rotates with an angular velocity of 5 rad/s and an angular acceleration of 60 rad/s^2, both clockwise, determine the force exerted on rod CD by collar B.
Homework Equations...
Homework Statement
A uniform rod of length L and mass m is supported as shown in the figure. A vertical cable at A suddenly breaks. Determine at this instant the angular acceleration of the rod and the tension in cables AE and BF.
Homework Equations
mass moment of intertia of bar...
I was just wondering what the equation for average angular acceleration is
At first i thought it was W avg = Delta Pheta/ Delta Time
but then i think that might be the Average Angular Speed formula...
Any ideas? i know it's a simple question so hopefully no one will get annoyed =P
Homework Statement
A person is riding a bicycle, and its wheels have an angular velocity of +20.0 rad/s.
Then, the brakes are applied and the bike is brought to a uniform stop.
During braking, the angular displacement of each wheel is +10.0 revolutions.
(a) How much time does it...
Homework Statement
A bowler throws a bowling ball of radius R = 11 cm down a lane. The ball slides on the lane, with initial speed vcm,0 = 6.0 m/s and initial angular speed 0 = 0. The coefficient of kinetic friction between the ball and the lane is 0.34. The kinetic frictional force fk acting...
Homework Statement
Given a frictionless pulley system with the pulley having a mass 1/3M and radius R, and two weights of mass M and 4M attached to a light, frictionless rope on either side of the pulley:
1) Find the acceleration of the blocks
2) Find the angular acceleration of the...
A small rubber wheel is used to drive a large pottery wheel. The two wheels are mounted so that their circular edges touch. The small wheel has a radius of 2.0 cm and accelerates at the rate of 7.2 rad/s^2, and it is in contact with the pottery wheel (radius 21.0 cm) without slipping...
Derive the expression \alpha=\frac{mgr}{I+mr^{2}}for the acceleration a=\alphar of the falling mass m
I don't even know what this question is asking...
Any ideas on how to approach this wonderful little puzzle?
A)If it took 0.480 s for the drive to make its second complete revolution, how long did it take to make the first complete revolution?
B)What is its angular acceleration, in rad/s^2?
please help
Homework Statement
A solid cylinder of 24 cm radius is postioned on a frictionless plane inclined at 30 degrees above horizontal. A force F is exerted by a string wrapped around the spool. When F has a certain critical value the center of mass of the spool does not move. When this is the...
Someone actually posted this exact problem 4 months ago, but here it is. There wasn't an answer.
Homework Statement
Heron of Alexandria invented the steam jet engine in the first century A.D. One of his many inventions, the one shown below was invented for amusement but employs many...
Homework Statement
http://img248.imageshack.us/img248/1639/cylinderjl0.jpg
A uniform cylinder with a radius of R and mass M has been attached to two cords and the cords are wound around it and hung from the ceiling. The cylinder is released from rest and the cords unwind as the cylinder...
[SOLVED] Grindstone angular acceleration
Homework Statement
Object: a disk-shaped grindstone of mass 1.69 kg and radius 7.95 cm that operates at 707 rev/min. When the power is shut off, you time the grindstone and find it takes 32.1 s for it to stop rotating. What is the angular acceleration...
Homework Statement
Starting from rest at t = 0s, a wheel undergoes a constant angular acceleration. When t = 3.9s, the angular velocity of the wheel is 6.9 rad/s. The acceleration continues until t = 19s, when the acceleration abruptly changes to 0 rad/s^2. Through what angle does the wheel...
Impossible "angular acceleration" problem
Homework Statement
The figure below shows a hollow cylindrical tube of mass M = 1.2 kg, L = 1.9 m, and moment of inertia ML2/10. Inside the cylinder are two disks of mass m = 0.6 kg, separated by a distance l = 0.8 m, and tied to a central post by a...
Homework Statement
A wheel is subjected to uniform angular acceleration. Initially its angular velocity is zero. During the first 1-s time interval, it rotates through an angle of 88.6degrees.
(a) Through what angle does it rotate during the next 1-s time interval?
(b) Through what angle...
Homework Statement
State the Relatrionship between radial and angular acceleration.
Homework Equations
Well I presume the equations would be "radial acceleration = v(squared)/radius"
The Attempt at a Solution
I cannot find the equation for radial AND angular acceleration??
I...
Hey.
I have been working on a relative simple 2D physics engine for a game I am making, and as I was researching the subject (rigid body mechanics) I found this article on physics in games. This pretty much answers everything. Though this is one little thing that I cannot figure out. The...
I'm trying to write a small rigid-body physics program. I already have the linear forces part done, using Euler's method. This makes it easy to take the current forces and compute the next position.
The issue I'm having is that I don't know how to get the next angular position/velocity from the...
Homework Statement
Info on object:
Mass = 10kg
Radius = 0.20m
Lenght of spouts = 0.10m above surface of sphere. (The two spouts can be considered massless.)
The sphere is hollow and looks like this. The pressure inside is 1.5 atm and the pressure outside is 1.0atm...
Homework Statement
A person is riding a bicycle, and its wheels have an angular velocity of +19.5 rad/s. Then, the brakes are applied and the bike is brought to a uniform stop. During braking, the angular displacement of each wheel is +11.5 revolutions.
(a) How much time does it take for...
Homework Statement
A copper block rests 33.8 cm from the center of a turntable. The coefficient of static friction between the block and turntable is 0.52. The table starts from rest and accelerates with an angular acceleration of 0.226 rad/s².
Acceleration of gravity = 9.8 m/s².
After...
Guys i need some help here. Does anyone know how to find the angular acceleration?
Gear A (radius = 150mm, mass= 4kg and radius of gyration = 100mm) and gear B(radius = 450mm, mass= 10kg and radius of gyration= 300mm) rotate about their respective centrers. A constant clockwise torque of...
Homework Statement
A solid cylindrical disk has a radius of 0.16 m. It is mounted to an axle that is perpendicular to the circular end of the disk at its center. When a 45 N force is applied tangentially to the disk, perpendicular to the radius, the disk acquires an angular acceleration of 110...
Homework Statement
Part One:
Imagine a hollow sphere of radius R and mass M. It is welded to the end of a solid rod of length L, whose mass is also M. The rod is attached to the sphere in such a way that the whole assembly, when viewed from the side, looks like a lollipop. (That is, the...
hi all,
just wanted some advice on calculating a rate of deceleration of a moving vehicle, if we work out the angular acceleration of the wheel.
so angular acceleration is dw/dt and is given as dw/dt=(m1-m2)/I
(i.e moments of force divided by moments of Inertia)
dw/dt is rad/s^2 and...
A fan blade rotates with angular velocity given by omega_z(t) = gamma - Beta(t)^2 .
Calculate the angular acceleration as a function of time.
I don't even know where to begin and my book is all but useless. Any ideas?
[b]1. rotating door is made from four rectangular glass panes, as shown in the drawing. The mass of each pane is 95 kg. A person pushes on the outer edge of one pane with a force of F = 80 N that is directed perpendicular to the pane. Determine the magnitude of the door's angular acceleration...
A pulsar is a rapidly rotating neutron star that emits radio pulses with precise synchronization, there being one such pulse for each rotation of the star. The period T of rotation is found by measuring the time between pulses. At present, the pulsar in the central region of the Crab nebula has...
Homework Statement
Compact Disc. A compact disc (CD) stores music in a coded pattern of tiny pits 10^-7 m deep. The pits are arranged in a track that spirals outward toward the rim of the disc; the inner and outer radii of this spiral are 25.0 mm and 58.0 mm, respectively. As the disc spins...
Homework Statement
A wheel accelerates from rest to 59 rad/s at a rate of 29 rad/s². How many revolutions the wheel turned while accelerating?Homework EquationsThe Attempt at a Solution
I'm confused, I suck at this kind of problem. I got change in angular velocity which would be 59rad/s, and...
I am having a bit of trouble with the following problem.
A cyclist starts from rest and pedals so that the wheels make 8.5 revolutions in the first 4.6 s. What is the angular acceleration of the wheels (assumed constant)?
I multiplied 8.5 by 2pi and then divided by 4.6 sec. I get an answer...
I am having a bit of trouble with the following problem. What should I do to start?
A cyclist starts from rest and pedals so that the wheels make 8.5 revolutions in the first 4.6 s. What is the angular acceleration of the wheels (assumed constant)?
i haven't been able to figure this one out... i have trouble following the explantion from my instructor. thanks for any help in advance
A rigid object consists of a point mass of 2 kg momentarily located at (-3, 2) m with a force of (6, 2) N acting on it, a second point mass of 3 kg...
The problem is:
The angular speed of a propellor on a boat increases with constant acceleration from 50 rev/min to 150rev/min in 2.5s.What is the angular acceleration of the propellor?
I'm not sure how to go about the problem.So far I've converted the 50rev/min and the 150rev/min to...