【单选题】(ZHCS1-33 - 角动量守恒)两个质量都为 100kg 的人,站在一质量为 200kg 、半径为 3m 的水平转台的直径两端.转台的固定竖直转轴通过其中心且垂直于台面.初始时,转台每 5s 转一圈.当这两人以相同的快慢走到转台的中心时,转台的角速度 ω 为( ) ( 已知转台对转轴的转动惯量 J = MR 2 /2 ,计算时忽略转台在转轴处的摩擦 ) 。
【判断题】“Suddenly the line went limp. There is a break somewhere.” In this sentence, the word “break” can be translated as “休息”.
【单选题】Suddenly there a loud sound when the clock fell to the floor.
【单选题】Suddenly there ____ a loud sound when the clock fell to the floor.
【单选题】已知OA、OB、OC三射线两两成60°角,则OA与平面OBC所成角的余弦值等于( )
【单选题】Suddenly there is a loud voice ___ the tree. A. below B. above C. on
【单选题】1 33 5 . 已知 A 、 B 两 点 间边 长 D A B = 1 85 . 35m , AB 边的方位 角 α A B = 145 ° 3 6 ′, 求 B 、 A 两点间 的坐 标 增量△ X B A 为( ) m
【单选题】Suddenly there is a loud voice ___ the tree.
【单选题】If there is an of something unpleasant, such as violence or a disease, it suddenly starts to happen.