[填空题]
A small 650-gram ball on1g09wsf l u o+vxg)p:j the end of a thin, light rod s6aj2t0 7msv qis rotated in a horizontal circle of radius 1.2 m. Calculate 07svstq jma26 (a) the moment of inertia of the ball about the center of the circle, $kg \cdot m^2$ (b) the torque needed to keep the ball rotating at constant angular velocity if air resistance exerts a force of 0.020 N on the ball. Ignore the rod’s moment of inertia and air resistance. $m \cdot N$