Consider a 9·kg disk with a radius of 0.9·m and rotating about an axis passing through its center.
(a) What is its rotational inertia? ______ kg·m2 ?
(b) Suppose the disk is rotating counterclockwise and speeding up with a rotational acceleration of 4·rad/s2. What is the net torque acting on the disk? _____N·m?
what direction clockwise or counterclockwise?
(c) Suppose the torque you found for the last part is being produced by a force applied at a point 0.8·m from the axis. If the direction of the force is perpendicular to a line from the axis to that point, what is the magnitude of the force? _____N?