Angular acceleration Definition and 551 Threads

Homework Statement A grindstone, initially at rest, is given a constant angular acceleration so that it makes 20.0 rev in the first 8.00 s. What is its angular acceleration? (a) 0.313 rad/s2 (c) 2.50 rad/s2 (e) 3.93 rad/s2 (b) 0.625 rad/s2 (d) 1.97 rad/s2Homework EquationsThe...

According to what I've read, I was told that 1) s = r*theta 2) angle("theta"): theta(t) in radians 3) angular velocity ("omega"): omega(t) = d/dt theta(t) in rads/s 4) angular acceleration ("alpha"): alpha(t) = d/dt omega(t) in rad/(s^2) However I do not understand the concept of this. I...

Homework Statement My guess is no because if you have a ball on a string, for there to be angular acceleration, the angular velocity must increase so you need an increasing tangential speed, so your centripetal acceleration must increase (α=v2/r)... but I'm not sure. One other question...

1. Homework Statement The system shown in the diagram contains two blocks, of masses 1.9 kg and 5.7 kg, connected by a light string over a pulley of radius 0.15 m and rotational inertia 2.8 kg m 2 . The block of mass 5.7 kg is free to slide on a horizontal frictionless surface and the pulley is...

Experts, I need to find out the centrifugal acceleration on a ball of mass m placed at a distance R from one end of the rod, and that end is being pivoted to rotate the rod..Of angular acceleration is alpha, is it correct to say, Centripetal / centrifugal (in case that the ball remains...

Homework Statement PROBLEM: You have a horizontal grindstone (a disk) that is mass m, has a radius r, and is turning at f in the positive direction. You then press a steel axe against the edge with a force of F in the radial direction. RANDOMIZED VARIABLES: m= 95 kg r= 0.33 m f= 92 rpm F= 25...

Homework Statement /* Intro, personal: I am taking Studio Physics 1 at FSU this summer semester. We have an online homework assigned weekly via a program called ExpertTA. This question has been giving me the HARDEST time and I seriously just need some help on it. I have completed and submitted...

Homework Statement A 12 kg mass is attached to a cord that is wrapped around a wheel of radius r = 10 cm (Fig. 8.20). The acceleration of the mass down the friction-less incline is 2.0 m/s^2/. Assuming the axle of the wheel to be friction-less, determine (a) the tension in the cord, (b) the...

Homework Statement A pulley in the shape of a cylinder of mass 5 kg and radius 0.6 m has a force of magnitude 30 N exerted tangentially on it. Find the angular acceleration of the pulley and its angular velocity after 3 s, assuming it starts from rest. Homework Equations T = Ftr T = mr^2a...

A grindstone,initially at rest,is given a constant angular acceleration so that it makes 20.0 rev? A grindstone,initially at rest,is given a constant angular acceleration so that it makes 20.0 rev in the first 8.00 s. What is its angular acceleration Answer is 3.93 rad/s^2 My attempt...

Homework Statement A turntable moves from rest to an angular speed of 45 rev/min in 1.5 s. What is its average angular acceleration? Homework Equations ω = ωo + \alphat The Attempt at a Solution I first converted 45 to radians by multiplying it by pi 45(3.14152654)/180 = .79 rad...

Homework Statement Consider a uniform rod of mass 12kg and length 1.0m. At its end, the rod is attached to a fixed, friction-free pivot. Initially the rod is balanced vertically above the pivot and begins to fall (from rest) as shown in the diagram. Determine, a) the angular acceleration of...

Homework Statement If a dynamometer is set to move at 180 deg/s and it takes 0.18 seconds to reach that speed. What was the angular acceleration of the test arm in radians/s/s to get to that velocity? Give your answer rounded to two decimal places and do not include units in answer...

Homework Statement A 100 kg slender rod is lifted on the left end until the angle between the ground and the right end is 30 degrees. The right end is still in contact with the ground. The coefficient of friction between the rod and the ground is .5 and the length of the rod is 2.1 m...

Homework Statement Consider a thin 14 m rod pivoted at one end. A uniform density spherical object (whose mass is 9 kg and radius is 3.2 m) is attached to the free end of the rod and the moment of inertia of the rod about an end is Irod =1/3mL^2 and the moment of inertia of the sphere about its...

Hello Firstly i just registered, I am a final year computer science student and I am busy working on my thesis (the deadline is fast approaching) I am working this application of a rocket going into orbit and physics is not my forte. I need some help on converting the gimbal of a rocket...

Homework Statement There is strong evidence that Europa, a satellite of Jupiter, has a liquid ocean beneath its icy surface. Many scientists think we should land a vehicle there to search for life. Before launching it, we would want to test such a lander under the gravity conditions at the...

Hi I have calculated angular acceleration which changes with time. I also have a moment(torque) which also changes with time and a fixed moment of inertia. Is there an equation or a way for me to work out the change in angle with respect to time using this information? If not, what other...

I am writing a lab report for an experiment where we used a rotary motion sensor with different sized disks to find angular acceleration as a string attached to a falling weight unraveled and accelerated the disk. I am having confusion with my graph results and am wondering if they are correct...

Homework Statement Assume your arm is a solid rod, 0.740 m in length, free to rotate about your shoulder (so its moment of inertia is (1/3)ML^2). If you hold your arm out sideways, and then completely relax your muscles, what is the initial downward angular acceleration of your arm? Homework...

Homework Statement A thin, uniform stick of length 2.1 m and mass 3.9 kg is pinned through one end and is free to rotate. The stick is initially hanging vertically and at rest. You then rotate the stick so that you are holding it horizontally. You release the stick from that horizontal...

During the time a compact disc (CD) accelerates from rest to a constant rotational speed of 477 rev/min, it rotates through an angular displacement of 0.250 rev. What is the angular acceleration of the CD? I converted 477 rev/min into 49.95 rad I converted 0.250 rev to radians which is 1.57 rad...

I understand that the torque caused by the friction must cause an angular acceleration, and it makes sense that the angular velocity increases from the bottom to the top so if there was a particle on the rim, as it went upwards it's speed would increase but what happens when it comes down again...

A grindstone, initially at rest, is given a constant angular acceleration so that it makes 20.0 rev in the first 8.00 s. What is its angular acceleration? I don't know which angular formula to use and how many are out there? I am so confused

Problem(physics class 201/Portland Community College) During the time a compact disc (CD) accelerates from rest to a constant rotational speed of 477 rev/min, it rotates through an angular displacement of 0.250 rev. What is the angular acceleration of the CD? (a) 358 rad/s2 (c) 901 rad/s2...

Homework Statement A man jumps at a fence. The fence hits the ground in 0.81 seconds, and the height of the fence is 1.24 meters. What is the angular acceleration of the fence? What is the force exerted by the man on the fence? The fence has a mass of 40 kg. Homework Equations...

Homework Statement A circular disk with the mass m and radius r is hanging from two ropes with length l when suddenly the rope ED snaps. For this moment, find: a, The angular acceleration for the rope OB, the angular acceleration for the disk b, The force T acting in OB The Attempt at...

For a rotating body, (angular acceleration x radius)= Acceleration of center of mass ? But a rotating body can have angular acc. even if it is not translating. what is wrong?

Homework Statement A phonograph turntable with an initial angular velocity of 78 rpm continues turning for 40 rotations after being switched off. What is the angular deceleration of the turntable? Assume constant angular deceleration. Homework Equations \alpha=(\omega-\omega0)/t...

Homework Statement 1) A solid cylinder of mass M = 1.54 kg and radius r = 0.100 m pivots on a frictionless bearing. A string wrapped around the cylinder pulls downward with a force F that equals the weight of a 0.590 kg mass, i.e., F = 5.782 N. Calculate the angular acceleration of the...

So my teacher said that an object farther from the center experiences greater centripetal acceleration. How is that possible? let's say we have a sun + planet system. F = GmM/r^2 so when the planet's r is greater, wouldn't the force become lower compared to the planet being closer to the sun?

Homework Statement A massless beam is supported only at one point, called the pivot point, as shown in the diagram. A block with mass m1 sits at the left end of the beam, a distance L1 from the pivot point. A block with mass m2 sits at the right end of the beam, a distance L2 from the pivot...

Homework Statement Assume that a 1.20-kg ball is thrown solely by the action of the forearm, which rotates about the elbow joint under the action of the triceps muscle, the figure. The ball is accelerated uniformly from rest to 9.5m/s in 0.38s , at which point it is released. Assume that the...

I've attached a screenshot of this particular question. I was able to figure out part A but I'm having some difficulty with part B. Relevant equations: T = I*alpha I = .5mr^2 (for a solid cylinder like the grinding wheel) F = ma Attempt at solution: I've gotten as far as setting up...

Homework Statement A string is wrapped around a pulley of radius 3.45cm , and a weight hangs from the other end. The weight falls with a constant acceleration 3.00m/s2 . What's the angular acceleration of the pulley? Homework Equations i'm writing out the equations i would think that...

Homework Statement An object travels counterclockwise on a circular path with radius R and constant angular acceleration α, so that vector r(t) = R cos(αt^2/2) i^+ R sin(αt^2/2) j^  Homework Equations b. Find the time T when the object made a single revolution and returned to...

Consider a massless string going over a massless frictionless pulley with masses M1 and M2 at the end of the string. The tension in the string would be same. The torque equation of the pulley says (T1-T2)=Iα .Now L.H.S is zero since T1=T2 and also I=0 . So,we have a condition 0=(0)(α)...

Homework Statement A mass of 0.5kg is suspended from a flywheel. If the mass is released from rest and falls a distance of 0.5m in 1.5s. ( mass of wheel = 3kg, Radius = 0.3m, Radius of gyration = 212mm ). Calculate : a:The linear acceleration of the mass? b: The...

Is there a way to calculate angular acceleration from the change in angular velocity and the change in the angle without considering time? How would you accomplish this?

Homework Statement Find angular acceleration in deg/sec^2 given the following factors: - Total mass: 4889 kg - Moment of inertia: 4620 kg*m^2 - Moment arm length from center of mass: 1.5 meters - Force on moment arm tangent to mass: 1779 Newtons Homework Equations torque = force...

hi, I've calculated ω=5 rad/s How can I calculate angular acceleration (α) I've Mass, M=4Kg Radius, R = 2m and time taken by each single revolution, T=3sec.

Homework Statement Two identical masses with a mass of m each are connected by a rigid bar of negligible mass and rotate in a vertical plane in an anti-clockwise direction. Homework Equations If the system is released from rest when it is in a horizontal position, determine the...

I need to calculate the angular velocity of a 2kg mass rotating in a horizontal circle of 2m radius where 1 revolution takes 4 seconds ω=v/r My attempt was this : 4/360=.0111111×57.3=.636rs.

Hi, I have the following problem that I'm lost on. The answer is 41.4 rad/s2 but I don't understand how to arrive at it.Homework Equations ƩT=I(alpha) I=1/3 ML2 for a rod with axis through one end. The Attempt at a Solution I solved the above equations to get (alpha)=T/I, but no matter what...

Homework Statement Two concentric disks are welded together with a small hole through the center. This two disk unit is mounted onto a frictionless horizontal axle through the center hole. Two strings are attached and wound in opposite directions around the outer perimeter of each disk and...

Homework Statement A 12.0-kg box resting on a horizontal, frictionless surface is attached to a 5.00-kg weight by a thin, light wire that passes over a frictionless pulley. The pulley has the shape of a uniform solid disk of mass 2.00kg and diameter 0.500m. After the system is released, find...

Homework Statement A uniform, straight rod with mass M and length L can rotate about a horizontal axis A in a distance L/4 from the rods end. Vi can disregard friction. Gravity is 9.81 m/s^2. (drawing included at the bottom) 1) Find an expression for the moment of inertia of the rod at point...

Homework Statement The circular disk of 595-mm radius has a mass of 16 kg with centroidal radius of gyration = 500 mm and has a concentric circular groove of 220-mm radius cut into it. A steady force T is applied at an angle θ to a cord wrapped around the groove as shown. If T = 41 N, θ = 39°...

Im a fairly new to physics and I have a homework question off mastering physics which is , A wheel is spinning at 43rpm with its axis vertical. After 15 sec , it's spinning at 61rpm with its axis horizontal. Find (a) the magnitude of its average angular acceleration and (b) the angle the average...

Homework Statement Determine the angular acceleration of the uniform disk if (a) the rotational inertia of the disk is ignored and (b) the inertia of the disk is considered. The system is released from rest, the cord does not slip on the disk, and bearing friction at O may be neglected. The...