Angular acceleration Definition and 551 Threads

If a certain car, going with speed v, rounds a level curve with a radius R, it is just on the verge of skidding. If its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is: Answer is 4R.. but I don't understand why? I know the...

A wheel of radius 0.2m is mounted on a frictionless horizontal axis. The rotational inertia of the wheel about the axis is 0.05kg(m^2). A massless cord wrapped around the wheel is attached to a 2kg block that slides horizontally. If a horizontal force of magnitude P=3N is applied to the...

Two masses (mA= 2 kg, mB= 4 kg) are attached to a (massless) meter stick, at the 0 and 75 cm marks. The system is then hung from a string, so that it stays horizontal. Now, if mass B was removed, and no additional force was supplied, calculate the size of the angular acceleration of the meter...

Angular Acceleration/ Find angle in period -- PLEASE help! I'm having trouble with part "B" please help. A.)A dentist's drill starts from rest. After 4.95 s of constant angular acceleration, it turns at a rate of 28600 rev/min. Find the drill's angular acceleration. An- swer in units of...

The problem states: when the play button is pressed, a CD accelerates uniformly from rest to 450 rev/min in 3.0 revolutions. If the CD has a radius of 6.0-cm and a mass of 17-g, what is the torque exerted on it? I used the the forumla tau = I * alpha; I = .5(0.017)(0.06)^2 = 3.06E-5; in...

M, a solid cylinder (M=1.59 kg, R=0.127 m) pivots on a thin, fixed, frictionless bearing. A string wrapped around the cylinder pulls downward with a force F which equals the weight of a 0.750 kg mass, i.e., F = 7.357 N. Calculate the angular acceleration of the cylinder. I used, I*alpha= mgr...

A rod of length 57.0 cm and mass 1.90 kg is suspended by two strings which are 41.0 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. I tried using torque= I* alpha torque= L x f= (.57)(18.62)=10.6 I got from Newton's...

A 6.59 kg block is released from A on a frictionless track, that slopes down until it reaches the floor, then loops in a circle(kinda like the hotwheels loops). Determine the angular acceleration of the block, alpha, about O, the axis of the loop, at the point P, which is located 45 degrees...

Hi, I need help with the following problem. A skater does a pirouette at the rate of 2.0 rev / second and then stop within 3/4 rev. Assume that the angular decceleration is constant and calculate its magnitude. I tried to compute it but I found -18 rad/s2. BUt the textbook gives -17...

An interesting question a prof posed in class to us one day: A bicycle wheel is upsidedown and is spinning. It has radius R. As it is raining, water droplets fly off tangentially from the bicycle. You measure the heights of the droplets flying off vertically from the bicycle (at the point...

A drum of radius R rolls down a slope without slipping. Its axis has acceleration 'a' parallel to the slope. What is the drum's angular acceleration? Please help me solve in polar coordinates.

A uniform rod (mass=2.0 kg, length=.60m) is free to rotate about a frictionless pivot at one end. The rod is released from rests in the horizontal position. What is the magnitude of the angular acceleration of the rod at the instant it is 60 degrees below the horizontal? Please help! I...

Hi, I have a problem that I just can't seem to figure out. Here it is: Four masses are arrnaged as shown below. They are connected by rigid, massless rods of lengths 0.75 m and 0.50 m. What torque must be applied to cause an angular acceleration of 0.75 rad/s^2? A--------B l...

A cyclist starts from rest and pedals such that the wheels of his bike have a constant angular acceleration. After 10.0 s, the wheels have made 54 rev. What is the angular acceleration of the wheels? Use units of "rad/s\^{}2". If the radius of the wheel is 36.0 cm, and the wheel rolls without...

1) A solid cylinder of mass M = 1.14 kg and radius R = 6.3 cm pivots on a thin, fixed, frictionless bearing (see Figure). A string wrapped around the cylinder pulls downward with a force F = 4.606 N. What is the magnitude of the angular acceleration of the cylinder? Use units of "rad/s\^{}2"...

1) A solid cylinder of mass M = 1.14 kg and radius R = 6.3 cm pivots on a thin, fixed, frictionless bearing (see Figure). A string wrapped around the cylinder pulls downward with a force F = 4.606 N. What is the magnitude of the angular acceleration of the cylinder? Use units of "rad/s\^{}2"...

More questions! A rotating door is made from four rectangular glass panes, as shown in the drawing. The mass of each pane is 91 kg. A person pushes on the outer edge of one pane with a force of F = 58 N that is directed perpendicular to the pane. Determine the magnitude of the door's angular...

Hey again. It's that time of week, and once again I'm stumped. There are three problems, but we'll take them one at a time. The first is as follows: A certain CD has a playing time of 68 minutes. When the music starts, the CD is rotating at an angular speed of 4.8x10^2 revolutions per minute...

PROBLEM: A rigid rod of mass 8.70 kg and length 2.30 m rotates in a vertical (x,y) plane about a frictionless pivot through its center. Particles m1 (mass=4.30 kg) and m2 (mass=2.60 kg) are attached at the ends of the rod. Determine the size of the angular acceleration of the system when the...

M, a solid cylinder (M=1.99 kg, R=0.133 m) pivots on a thin, fixed, frictionless bearing. A string wrapped around the cylinder pulls downward with a force of F which equals the weight of a 0.830 kg mass, i.e, F=8.142 N. Calculate the angular acceleration of the cylinder. I tried drawing a...

I'm trying to solve this problem, but keep going around and not getting the correct equation. A wheel of radius R, mass M, and moment of inertia I is mounted on a frictionless horizontal axle. A light cord wrapped around the wheel supports a body of mass m. At time t=0, the body is let go...

A wheel on a game show is given an initial angular speed of 1.22 rad/s. It comes to rest after rotating through 3/4 of a turn. Find the average torque exerted on the wheel given that it is a disk of radius 0.71m and a mass 6.4kg. I'm lost. I don't really know where to begin. I know the...

A block of mass 2.00 kg and a block of mass 6.00 kg are connected by a massless string over a pulley in the shape of a solid disk having a radius of .25 m and mass 10 kg. These blocks are allowed to move on a fixed block-wedge of angle 30 degrees. Friction = .360 for both blocks. Ok I don't...

If a rotating object starts at rest and completes one rotation in 4s, what is its angular acceleration assuming its angular acceleration is constant? \omega=\frac{2\pi}{t} \omega=\frac{2\pi}{4} \omega=\frac{\pi}{2} \alpha=\frac{\omega}{t} \alpha=\frac{\frac{\pi}{2}}{4}...

rod -- angular acceleration A long uniform rod length L and mass M is pivoted about a horizonal, frictionless pin passing through one end. The rod is released from rest in a vertical position. The instant the rod is horizontal, what is the magnitue of its angular acceleration. It's angular...

A discus thrower accelerates a discus from rest to a speed of 25 m/s by whirling it though 1.25 rev. Assume the discus moves on the arc of a circle 1m in radius. Determine the magnitude of the angular acceleration of the discus: ω=angular velocity ω=v/r=25m/s / 1m = 25rad/s ω^2=2ad...

I need some help, I've never dealt with a torque problem that uses friction or mechanical energy. This is the problem: Attached to each end of a thin steel rod of length 1.00 m and mass 6.70 kg is a small ball of mass 1.10 kg. The rod is constrained to rotate in a horizontal plane about a...

HELP! I keep getting a solution that is not part of the choices. Where am I messing up? A grindstone, originally rotating at 126 rad/s undergoes a constant angular acceleration so that it makes 20.0 rev in the first 8.00s. What is the angular acceleration? a) 0.313 rad/s2 b)...

My main goal was the find the angular acceleration of the seesaw. The swing bar of mass is pivoted at a different point, as shown in the figure. Find the magnitude of the angular acceleration of the swing bar. Be sure to use the absolute value function in your answer, since no comparison...

For a disk in the x-y plane that is rotating about the z-axis which travels through its center of mass, how does the angular acceleration relate to the linear acceleration of a particle on the body? Is the direction and the magnitude both affected? How do we calculate these in vector form? I...

A rotating wheel requires 3.00s to rotate 37.0 revolutions. Its angular velocity at the end of the 3.00-s interval is 98.0rad/s. What is the constant angular acceleration of the wheel? What i did was i used average w=delta(theta)/delta time. Then i used average w=radical(w^2+wo^2) to find...

A dumbbell consists of a slender rod of negligible mass and small spheres attached to each end with mass 12-kg and 6-kg respectively. It is pivoted at its center about a fixed horizontal frictionless axle and initially held in place horizontally. The length of the rod is 50 centimeters and...

Two pulleys are glued together and placed on a common axis. The total moment of interia for the pulleys is 22.0 kgm^2. The radius of the smaller pulley is 0.170 meters and hanging from it is a mass 5.94 kg. The large pulley has a radius of 0.510 meters and hanging from it is a mass of 8.41 kg...

Can someone walk me through this problem? A power drill reaches 13164 rpm in 1.01 seconds. What is the angular acceleration? The answer listed is 3.791 rad/s2, but I don't know how to get there. So far, I did (13164 rev x 2pi)/60 seconds to get 1378.5 rad/s (which is 'w', right)? but...

A hammer thrower accelerates the hammer (mass = 7.3 kg) from rest within four full turns (revolutions) and releases it at a speed of 27.2 m/s. Assuming a uniform rate of increase in angular velocity and a radius of 2.0 m, calculate (a) the angular acceleration, (b) the (linear) tangential...

Hello, I'm stuck on this problem and I think its because I am lacking the calculus to get the correct answer. A shaft is turning at 65 rad/s at time = 0. After, its angular acceleration is given by: a= -10.0 rad/s^2 - 5.00t rad/s^3 where t is the elapsed time. Find its angular speed...

Hmmm. I have a question... We know that the tangential acceleration (At) is equal to the radius (R) multiplied by angular acceleration (Ar), of which At and Ar are vector components. At = R Ar Then I was told that Ar = At/R is not a vector equation. Why is that true? ~Seph :confused:

Hello everyone! I need to solve the angular acceleration on a sunglass bin on an over head console of a car. The sunglass bin rotates open. It has a torsional spring and gravity that forces it to open and a small rotary damper that slows it down. There is a gear on the sunglass bin and on...

I think I'm starting to abuse this forum. Anyways, it seems that I haven't grasped the concept of angular acceleration yet since I'm having trouble solving this problem: Suppose I have a disc laying on the x-y plane with center at the origin. Suppose the disc is rotating about the z-axis with...

Setting the Stage: A uniform sphere has a mass of 100 kilograms and a radius of 10 meters. It is located at [0,0,0] It is in static equilibrium. We are in constant time. We are in a vacuum, there is no gravity, friction, or any other forces to act upon our sphere. We are using a...

Heres the problem. I'm trying to solve it at the moment, and I'll be posting what I have done so far. I'm very short on formulas for this so I will need help. Thanks a lot. 1) a) Determine angular acceleration of a wheel, which has a velocity of 200 rad/min after rotating for 1.5s from...

I missed a week of school because of a virus. During that week, I missed taking a lot of physics notes. When I returned, I received a problem from my teacher that he wants me to solve. I have the notes now but I don't understand them because they weren't taught to me, so may someone please help...

Hi everyone, I'm just a bit confused about calculating angular acceleration and knowing when it is constant or not. Here's the problem: A gymnast is swinging on a horizontal bar, and we're asked to calculate the forces in his hands when he is at 90 degrees with the bar. He was originally...

A bicycle has wheels of 1.2m diameter. the bicyclist accelerates from rest with constant acceleration to 24km/h in 14.0s. What is the angular acceleration of the wheels? If the bicycle is going forwards relative to the ground with a speed of 24km/h, then, all points on the tread are moving...

Okay, so there's a car traveling 97km/h (26.94 m/s). It's wheels have a diameter of 76cm (0.76 m), so the radius of the wheels are 0.38 m. I'm supposed to find the angular speed of the wheels about the axle. Can I say the speed of a tangent from the wheels is 26.94 m/s and use that to find...

At the time, it is cramped in the microcosmos of forum Theory Development; therefore I scrambled out to take the fresh air among the admirers of cosmic space. I have the important occasion to talk about gravitation and inertia. I managed to find the formula for gravitational electron mass in...

I don't really know what to do on this problem. So if someone could get me pointed in the right direction I would appreciate it. The tub of a washer goes into its spin-dry cycle, starting from rest and reaching an angular speed of 7.0 rev/s in 13.0 s. At this point the person doing the...

Problem 5. given:g=9.81m/s^2. A light string 1.20 m long is wrapped around a solid cylindrical spool with a redius of 0.0195 m and a mass of 0.380 kg. A 8.40 kg mass is then attached to the free end of the string, causing the string to unwind from the spool. a. What is the angular...

The Tub of a washer goes into a spin cycle, starting from rest and gaining angular speed steadily for 8 s, when it is turning at 5 rev/s. At this point the person doing the laundry opens the lid, and a safety switch turns off the washer. The tub smoothly slows to rest in 12s. Through how many...

How do you find angular acceleration when all you have is angular and linear velocity and a radius of a circle? I tried to use the kinematics but all of them require time or theta.