Angular acceleration Definition and 552 Threads

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...

String is wrapped around the outer rim of a solid uniform cylinder that is free to rotate about a frictionless axle through its center. When the string is pulled with a force P tangent to the rim it gives the cylinder an angular acceleration alpha. If the cylinder had twice the radius, but...

The pulley shown in the illustration has a radius of 2.70 m and a moment of inertia of 39.0 kg∙m2. The hanging mass is 4.20 kg and it exerts a force tangent to the edge of the pulley. What is the angular acceleration of the pulley? All I have so far is the force exerted on the pulley by the...

Homework Statement See the image attached What power must be applied to this object to accelerate it from rest to an angular speed of 2.7 rad/s in 5.2 s about the x axis? Homework Equations P = W / t - torque * angular velocity The Attempt at a Solution P = [(0.5 m)*(7...

Homework Statement A cyclist starts from rest and pedals so that the wheels make 8.5 revolutions in the first 4.5 s. What is the angular acceleration of the wheels (assumed constant)? Homework Equations \alpha = \Delta\omega/ \Deltat The Attempt at a Solution I converted...

Homework Statement The rod is at rest and is released, what is the angular acceleration immediately after release? The pivot is frictionless, gravity is 9.8 m/s^2. Homework Equations Icm = (1/12)ML^2 => Inertia at center of mass, this was given in the problem, i don't think it's necessary...

Homework Statement A 2.70 kg bucket is attached to a disk-shaped pulley of radius 0.141 m and mass 0.792 kg. If the bucket is allowed to fall, A- What is linear acceleration? B- What is angular acceleration? C- How far does the bucket drop in 1.5 s? Homework Equations a=g/(1+ (I/mr^2))...

Hi guys Can u tell me what is the relationship between angular acc. of driveshaft and that of wheel. Remember to include final drive ratio in relation.

Homework Statement A wheel spins at 45rpm with its spin axis vertical. After spinning 15 sec, it is spinning at 60rpm with its axis horizontal. Find its average angular acceleration and the angle the avg acceleration vector makes with the horizontal.Homework Equations Sorry, I can't really do...

Homework Statement What is the tangential acceleration of a bug on the rim of a 8.0 in. diameter disk if the disk moves from rest to an angular speed of 75 revolutions per minute in 5.0 s? (b) When the disk is at its final speed, what is the tangential velocity of the bug? (c) One second...

Homework Statement A dentist's drill starts from rest. After 2.90 s of constant angular acceleration it turns at a rate of 2.20 x 10^4 rev/min. (a) Find the drill's angular acceleration (in rad/sec^2). (b) Determine the angle (in radians) through which the drill rotates during this period...

A potter's wheel moves uniformly from rest to an angular speed of 0.23 rev/s in 29 s.

Homework Statement A wheel rotating with a constant angular acceleration turns through 22 revolutions during a 9 s time interval. Its angular velocity at the end of this interval is 15 rad/s. What is the angular acceleration of the wheel? Note that the initial angular velocity is not...

Homework Statement The blades in a blender rotate at a rate of 7900 rpm. When the motor is turned off during operation, the blades slow to rest in 4.0 s. What is the angular acceleration as the blades slow down? Vi= 7900 rpm = 82.72860654 rad/sec (This may be my error) Vf= 0 t= 4 secsHomework...

I am trying to answer the following question: A cyclist starts from rest and pedals such that the wheels of the bike have a constant angular acceleration. After 12.0 s, the wheels have made 26 revolutions. What is the angular acceleration of the wheels? My attempt at a solution: This...

ive been trying to do this question all summer to no joy. I've got a flywheel in motion which then has a torque applied for short period and i need to find the angular acceleration. i know its something to do with inertia but I am completely lost cheers

Homework Statement A cable is around a pulley with: radius = 0.1 m moment of inertia = 0.15 kg * m(squared) The cable receives a pull of: force = 12 N Find the magnitude of the resulting angular acceleration of the puller. Homework Equations Average angular acceleration = Change...

Homework Statement A disk rotates with constant angular acceleration. The initial angular speed of the disk is 2π rad/s. After the disk rotates through 1π radians, the angular speed is 14π rad/s. What is the magnitude of the angular acceleration? Homework Equations w=w0+at The...

Homework Statement An amusement park game, shown in the figure (see attachment), launches a marble toward a small cup. The marble is placed directly on top of a spring-loaded wheel and held with a clamp. When released, the wheel spins around clockwise at constant angular acceleration...

Homework Statement A Pulley has mass M=4 kg and radius R=0.4 m. Assume that it is a uniform solid disk so that its moment of inertia is I= .5MR^2. A massless cord is wrapped around it and a tension force Ft is applied. The pulley starts from rest. After the tension force has been applied for...

A child riding a merry-go-round is sitting on a horse onto a stationary pole 10m from the center of the merry-go-round. The ride starts from rest and with constant angular accleration obtains an angular velocity of 2 rad/s in 10 seconds. It then continues at 2 rad/s for 15 seconds and then...

Note: This is similar to 2 previous questions I've seen here (https://www.physicsforums.com/showthread.php?t=261193"), and while this is my first post, I've lurked/found this site to really be helpful in getting me to be able to figure out how to solve problems I have with my physics homework...

http://img15.imageshack.us/img15/858/masteringf.jpg my attempt, \alpha= dw/dt 550-150 = 400 rev/min change 400/3.5 = 114 revs that wasn't right so i tried 114*60, which gives -6857 revs^-2 can someone help please? I'm not sure if I've got this whole revolution thing correct...

Homework Statement A 4 meter long rod is hinged at one end. The rod is initially held in the horizontal position, and then released as the free end is allowed to fall. What is the angular acceleration as it is released? Homework Equations Ang. Accel. = (Tan. Accel.)/(radius) The...

Homework Statement A board of mass m and length L is hinged to the ground. Attached to the board is a cup of negligible mass and is positioned Rc away from the hinge. Also on the edge of the board a ball rests. When the board is dropped from an angle of theta the ball is meant to be...

Homework Statement A mass attached to a 43.9 cm long string starts from rest and is rotated 35 times in 57.0 s before reaching a final angular speed. Determine the angular acceleration of the mass, assuming that it is constant and determine the angular speed after 57 sec. Homework...

When finding Angular Acceleration, how is it that -7.129 x 10-4 rev/s2 equal to -4.47800 x 10-3 rad/sec2? In other words, how does the unit conversion work?

Hello! May i ask a question? Why angular acceleration is positive if object rotating clockwise is slowing down? Thanks.

Homework Statement 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...

I feel really dumb, as this should be incredibly easy to figure out, but I keep getting the wrong answers. I am including the book's data so I can figure out how this needs to be done and then plug in my own values. Homework Statement Pilots can be tested for the stresses of flying...

Homework Statement A uniform rod is pivoted at its center and a small weight of mass M = 5.07 kg is rigidly attached to one end. You may neglect the size of the weight and assume it is located right at the end of the rod. Homework Equations Now suppose that the rod has length L = 5.4 m...

Homework Statement A uniform rod with of weight of 10 kg and length of 5.8 m is pivoted at its center and a small weight of mass 5.15 kg is rigidly attached to one end. You may neglect the size of the weight and assume it is located right at the end of the rod. The system is released from rest...

Homework Statement A uniform rod is pivoted at its center and a small weight of mass M = 5.07 kg is rigidly attached to one end. You may neglect the size of the weight and assume it is located right at the end of the rod. a) What vertical force, Fv, must be applied to the opposite end to...

From Angular Velocity to Angular Acceleration -- How? Homework Statement Calculate the vector acceleration as a function of angle for a mass rotating in a circle at the end of a string. The mass is rotating in the vertical plane, in the counterclockwise direction. \hat{i} and...

Homework Statement A car traveling on a flat (unbanked) circular track accelerates uniformly from rest with a tangential acceleration of 1.80 m/s2. The car makes it one quarter of the way around the circle before it skids off the track. Determine the coefficient of static friction between...

A centrifuge in a medical laboratory rotates at an angular speed of 3400 rev/min. When switched off, it rotates 48.0 times before coming to rest. Find the constant angular acceleration of the centrifuge. Relevent equations: ωf = ωi + αt My work: I found out the time by (48 rev)(1min/3400...

One of the first things we learn is that the Earth rotates very quickly (about once a day). We, as very imaginative 4/5/6 year old children, quickly realize the dangerous implications of this. However, as quickly as the fear beset us, we are calmed by our teacher/parent/television. "Gravity...

I have a wheel with a diameter of 26 inches that weighs 3900 lbs that is spinning at 100 MPH... How much torque is needed to accelerate the wheel to 109 mph in 2.0 secondsanswer must be in ft-lbs convert any units as necessaryplease show me the math so I can learn how to do this..I have a few...

a block with a mass of m=10kg is connected to a pulley with a mass of M=2.5kg and a radius of R=0.5m. what is 1) the angular acceleration of the pulley 2) the acceleration of the block 3) the tension in the rope connecting them? ----------------------------------------------- equations...

This my first post on this very helpful forum. So are angular displacement, velocity, and acceleration actually vectors? My Physics book does not really give me a straight answer. Plus, if they are, why do they not have the classic vector notation of the arrow above \theta, \omega, and...

Homework Statement http://img166.imageshack.us/img166/6047/cilinderox6.jpg Homework Equations Tangent Acceleration, Linear Acceleration The Attempt at a Solution I tried to made a free body diagram but i got confused with the inclined plane I am stuck there. Also with the...

Homework Statement I'm getting this problem wrong and I'm not quite sure why. The 200 g model rocket shown in the figure generates 4.0 N of thrust. It spins in a horizontal circle at the end of a 100 g rigid rod. What is its angular acceleration (in rad/s2)? Homework Equations...

Homework Statement wheel rotates w constant acceleration 3.65rad/s2 angular speed is 3.00 rad/s at t=0 a)what angle does wheel rotate between t=0 and t=3.67s? b)what is angular speed of wheel at 4.1s? Homework Equations wt+1/2alphat (3.00rad/s)(3.67t)+1/2(3.65rad/s2)(3.67)2=17.70rad...

Homework Statement Given that a wheel with w(1) = -44i, is mounted on a turntable with w(2) = 35k, determine overall angular velocity and acceleration. Give both magnitude and direction. Homework Equations a = w(1) X w(2) ? The Attempt at a Solution I got the correct angular...

Hello all, The other day I observed an occurrence in my Physics class which I do not understand. The teacher set up a rotating platform with a second platform attached to it, so it made a 45 degree angle with the rotating platform. He then proceeded to put a ball at the top of the second...

A rod of length 61.0 cm and mass 2.10 kg is suspended by two strings which are 37.0 cm long, one at each end of the rod. The string on side B is cut. Find the magnitude of the initial acceleration of end B.

Homework Statement A 0.023 g 1.0 inch long second hand on a wristwatch. Find its average angular acceleration? Homework Equations av=w/t The Attempt at a Solution so would i just do 0.023 g divided by 1 minute?

My friend in introductory physics came to me for help today. He has a test on angular momentum, acceleration etc. I figured, with me in upper-division physics courses, I'd be able to help him out. Well, I guess I was dead wrong. In half an hour I couldn't figure out a SINGLE THING. I don't...

Homework Statement A vertical grinding wheel is a uniform disk of mass 62 kg and radius 45 cm. It has a handle of radius 69 cm of negligible mass. A 25-kg load is attached to the handle when it is in the horizontal position. (a) Neglecting friction, find the initial angular acceleration of...

Homework Statement A propeller slows from 450 rev/min to 200 rev/min in 3.50 s. What is its angular acceleration? Homework Equations ac = v^2/r and v = rw The Attempt at a Solution I know this is probably a simple problem, but what do the variables in the relevant equations refer to?