[填空题]
Suppose David puts a 0.50-kg roc *kaq92ug-ctqg/dng -k into a sling of length 1.5 m6tjyd/eca5t 9 *(ygkm and begins whirling the rock in a nearly horizontal circle above his head, accelerating it from rest to a rate of 120 rpm after 5.0 s. What is the torque required to achieve thk m6/yd5eyt( ac*9jtg is feat, and where does the torque come from? $m \cdot N$
