The object shown in the figure below consists of a thin rod of length l = 23.3 cm and mass m = 1.20 kg with a solid sphere of diameter d = 10.0 cm and mass M = 2.00 kg attached to its top. The object is free to pivot about a frictionless axle through the bottom of the rod. The object is initially vertical and at rest when it starts to rotate clockwise. m M (a) After the combination rotates through 90 degrees, what is its rotational kinetic energy (in J)? J (b) What is the angular speed (in rad/s) of the rod and sphere? rad/s (c) What is the linear speed (in m/s) of the center of mass of the sphere? m/s (d) How does it compare with the speed had the sphere fallen freely through the same distance of 28.3 cm? (Express your answer as a percentage of Vfall") swing is ---Select--- V *Vfall by %.

A space station is coast me ted in the shape of a hollow ring of mass 5.00 104 kg. Members of the crew walk on a deck formed by the inner surface of the outer cylindrical wall of the ring, with radius r = 100 m. At rest when constructed, the ring is set rotating about its axis so that the people inside experience an effective free-fall acceleration equal to g. (Sec Fig. P11.29.) The rotation is achieved by firing two small rockets attached tangentially to opposite points on the rim of the ring, (a) What angular momentum does the space station acquirer (b) For what time interval must the rockets be fired if each exerts a thrust of 125 N?

A wheel starts from rest and in 12.65 s is rotating with an angular speed of 5.435 rad/s. a. Find the magnitude of theconstant angular acceleration of the wheel. b. Through whatangle does the wheel move in 6.325 s?

A rigid body with a cylindrical cross-section is released from the top of a 30 incline. It rolls 10.0 m to the bottom in 2.60 s. Find the moment of inertia of the body In terms of its mass m and radius r.

Find the net torque on the wheel in Figure P10.23 about the axle through O, taking a = 10.0 cm and b = 25.0 cm. Figure P10.23

The precession angular velocity of a gyroscope is 1.0 rad/s. If the mass of the rotating disk is 0.4 kg and its radius is 30 cm, as well as the distance from the center of mass to the pivot, what is the rotation rate in rev/s of the disk?

A digital audio compact disc carries data, each bit of which occupies 0.6 m along a continuous spiral track from the inner circumference of the disc to the outside edge. A CD player turns the disc to carry the track counterclockwise above a lens at a constant speed of 1.30 m/s. Find the required angular speed (a) at the beginning of the recording, where the spiral has a radius of 2.30 cm, and (b) at the end of the recording, where the spiral has a radius of 5.80 cm. (c) A full-length recording lasts for 74 min 33 s. Find the average angular acceleration of the disc. (d) Assuming that the acceleration is constant, find the total angular displacement of the disc as it plays. (e) Find the total length of the track.

Calculate the rotational kinetic energy of a 12-kg motorcycle wheel if its angular velocity is 120 rad/s and its inner radius is 0.280 m and outer radius 0.330 m.

A rod of length 20 cm has two beads attached to its ends. The rod with beads starts rotating from rest. If the beads are to have a tangential speed of 20 m/s in 7 s, what is the angular acceleration of the rod to achieve this?

Two spheres, one hollow and one solid, are rotating with the same angular speed around an axis through their centers. Both spheres have the same mass and radius. Which sphere, if either, has the higher rotational kinetic energy? (a) The hollow I sphere, (b) The solid sphere, (c) They have the same kinetic energy.