A.Money is important. B.Responsibility means more than salary. C.High salary secures better performance. D.Future income is more important than starting salary.
【单选题】如图所示,轮 O 在水平面上滚动而不滑动,轮心以匀速 vO =0.2m/s 运动,轮缘上固连销钉 B ,此销钉在摇杆 O 1 A 的槽内滑动,并带动摇杆绕 O 1 轴转动。已知:轮的半径 R =0.5 m ,在图示位置时, AO 1 是轮的切线,摇杆与水平面间的交角为 60 °。求摇杆在该瞬时的角速度和角加速度。