【简答题】平面机构如图所示,杆AB可在套筒C内滑动,曲柄OA绕轴O以匀角速度ω=2.5rad/s在平面内转动。在图示位置试求构件DC的角速度和角加速度。
【单选题】Which of the following can be learned from the text?
A.
People like Lynn Carr's cheesecakes very much.
B.
Lynn Carr's cheesecakes are sold to high school dropouts.
C.
Lynn Carr learned to make cheesecakes by taking courses.
D.
Without finishing high school, one cannot even make good cakes.
【简答题】均质细直杆OA长为ι,质量为m,A端固结一质量为m的小球(不计尺寸),如图所示。当OA杆以匀角速度ω绕O轴转动时,该系统对O轴的动量矩为( )。
【判断题】能工巧匠会把真本领教给一个不尊重自己的年轻人
【简答题】如图所示的机构中,曲柄长OA=r,以匀角速度ω绕水平轴O转动,BO=2r,则在图示∠BOA=90°的瞬时,BC摇杆转动的角速度大小ω BC =______,转向______。