A certain pulley is a uniform disk of mass 2.7 kg and radius 0.25 m. A rope applies a constant torque to the pulley, which is free to rotate without friction, resulting in an angular acceleration of 0.12 rad/s2. The pulley starts at rest at time t = 0 s. What is its rotational kinetic energy at t = 2.2 s?
w = at
E = Iw^2 / 2
I = mr^2 / 2
The moment of inertia is:
2.7 * 0.25^2 / 2 kg m^2
The angular velocity at time 2.2 sec. is:
0.12 * 2.2 rad / sec.
The rotational KE is:
(2.7 * 0.25^2 / 2) (0.12 * 2.2)^2 / 2
= 2.94 * 10^(-3) J.
A certain pulley is a uniform disk of mass 2.7 kg and radius 0.25 m. A...
A 2.7-kg 12-cm-radius cylinder, initially at rest, is free to rotate about the axis of the cylinder. A rope of negligible mass is wrapped around it and pulled with a force of 18 N. (a) Find the magnitude of the torque exerted by the rope. N · m (b) Find the angular acceleration of the cylinder. rad/s2 (c) Find the angular velocity of the cylinder at t = 0.70 s. rad/s
Two objects, A with mass mA=0.25 kg and B with mass mB=1.25 kg, are held at rest on a spring is released, A has a kinetic energy of 22 J and B has a kinetic energy of A) 110 J g is compressed between them. Immediately after the B) 5.5J C) 11 J D) 4.4 J E) 19.4 J 18. A certain wheel has a rotational inertia of 12 kg m2. As it turns through 5.0 rev its angular velocity...
#335. Rolling disk kinetics A uniform rigid disk of mass m = 6 kg and radius r = 4 m starts at rest on a flat ground as shown. Force Ď= 28î + 589 N acts at point P on the right edge, and gravity g = 9.8 m/s² acts vertically. The coefficient of friction between the disk and the ground is j = 0.75. D lo c. P What is the angular acceleration ā of the disk? Matlab/Mathematica input:...
A uniform disk with mass m = 9.07 kg and radius R = 1.36 m lies in the x-y plane and centered at the origin. Three forces act in the +y-direction on the disk: 1) a force 313 N at the edge of the disk on the +x-axis, 2) a force 313 N at the edge of the disk on the –y-axis, and 3) a force 313 N acts at the edge of the disk at an angle θ =...
A solid disk with a mass of 40 kg and a radius of 0.6 m can rotate around an axis through its center, perpendicular to the disk surface. At time t = 0 s, the disk is not turning. It has a constant angular acceleration ↵ and by t = 20 s it has completed 500 complete turns. Calculate the angular acceleration ↵. Calculate the angular velocity ! at t = 20 s. Calculate the rotational kinetic energy at t...
2. The pulley (disk) has a radius "R" and a mass "m". The rope does not slip over the pulley, and the pulley spins on a frictionless axle. The coefficient of kinetic friction between block A and the surface is "u. The system is released from rest and block B descends. Block A has a mass "2m" and block B has a mass "m Write out the forces and torque equations. Given [R, m, h, ], Determine: a. The acceleration...
Consider a uniform disk of radius R and mass m sliding down an incline making an angle θ with respect to the horizontal. The coefficient of kinetic friction between the disk and the surface is μk. The torque due to friction causes the disk to rotate as it slides down the incline. a) Compute the linear acceleration of the disk as it slides down the incline. b) Compute the angular acceleration of the disk as it slides down the incline....
A uniform disk of radius 0.455 m0.455 m and unknown mass is constrained to rotate about a perpendicular axis through its center. A ring with the same mass as the disk is attached around the disk's rim. A tangential force of 0.237 N0.237 N applied at the rim causes an angular acceleration of 0.129 rad/s2.0.129 rad/s2. Find the mass of the disk.Why is this wrong? A uniform disk of radius 0.455 m and unknown mass is constrained to rotate about...
A uniform disk of radius 0.551 m and unknown mass is constrained to rotate about a perpendicular axis through its center. A ring with same mass as the disk\'s is attached around the disk\'s rim. A tangential force of 0.229 N applied at the rim causes an angular acceleration of 0.103 rad/s2. Find the mass of the disk.
A uniform disk with mass m = 8.55 kg and radius R = 1.35 m lies in the xy plane and centered at the origin. Three forces act on the disk in the +y-direction (see figure below): (1) a force F1 = 335 N at the edge of the disk on the +x-axis, (2) a force F2 = 335 N at the edge of the disk on the ?y-axis, and (3) a force F3 = 335 N at the edge...