[填空题]
A small 650-gram ball on th.,j)p/u7nymyce9o lx e enduhotdqz;cb4/v. y+6w;hq+ w: s bmi8c of a thin, light rod is rotated in a horizontal circle of radius; chqw .;i/zwm coy 8+svtbu:dhq+64 b 1.2 m. Calculate (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. $m \cdot N$