A thin circular hoop of mass 1.0 ?? and radius 2.0 ? is rotating about an axis through its center  and perpendicular to its plane. It is slowing down at the rate of 7.0 ???/? 2 . The net torque acting  on it is

A diver performs a flip in the air. The radius of gyration is 0.43 when the diver initially leave the board and the diver is rotating at an angular velocity of 6.3 rad/sec. What is the linear velocity of the head when they decrease their radius of gyration to 0.24. The distance from the head to the center of gravity of the individual is 0.3 meters?

An object has a moment of inertia of 0.79 kg m2. Its angular velocity is increasing at the rate of 0.40 rad/s per second. What is the net torque (in N m2) on the object?

Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 1.00 s, it rotates 30.4 rad. During that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular velocity? (c) What is the instantaneous angular velocity of the disk at the end of the 1.00 s? (d) With the angular acceleration unchanged, through what additional angle (rad) will the disk turn during the next 1.00 s? (a) Number i Units (b) Number i Units (c) Number i Units (d) Number i Units >

A student holds a bike wheel and starts it spinning with an initial angular speed of 9.0rotations per second. The wheel is subject to some friction, so it gradually slows down. In the 10 s period following the inital spin, the bike wheel undergoes 70 complete rotations. Assuming the frictional torque remains constant, how much more time Δts will it take the bike wheel to come to a complete stop? The bike wheel has a mass of 0.625 kg and a radius of 0.315 m. If all the mass of the wheel is assumed to be located on the rim, find the magnitude of the frictional torque τf that was acting on the spinning wheel.

A counterweight of mass m = 3.60 kg is attached to a light cord that is wound around a pulley as shown in the figure below. The pulley is a thin hoop of radius R = 7.00 cm and mass M = 3.00 kg. The spokes have negligible mass. (a) What is the net torque on the system about the axle of the pulley? V N.m to the right along the axis of rotation v magnitude 2.4695 direction (b) When the counterweight has a speed v, the pulley has an angular speed w = v/R. Determine the magnitude of the total angular momentum of the system about the axle of the pulley. (3.705 Note that your numerical answer is multiplied by the symbol v in the answer box. kg • m)v (c) Using your result from (b) and 7 = L/dt, calculate the acceleration of the counterweight. (Enter the magnitude of the acceleration.) 6.925 The expression for the angular momentum in part (b) has a factor of v. How do you determine dL/dt, from this expression? m/s2

A constant torque of 25 N.m is apllied to a grindstone whose moment of inertia is 0.125kg.m^2. What is the angular speed (in rad/s) after the grindstone has made 10 revolutions? (Neglect friction)