[填空题]
Suppose David puts a 0.50-kg rockva(h +lio5 nn; t:u(bm into a sling of length 1.5 m and be(,s0 jf.nzc nq9ure+bgins whirling the rock in a nearly horizontal circle above his head, accelerating it fnc9.r0(sb eqzn+ ,f jurom rest to a rate of 120 rpm after 5.0 s. What is the torque required to achieve this feat, and where does the torque come from? $m \cdot N$
Post time 2025-2-18 20:00:22
