【简答题】图示质量为m的质点A相对于半径为R的圆盘由C点沿倾斜角为φ的斜槽CO滑向圆盘中心O,圆盘以匀角速度ω转动.设质点A在点C时相对圆盘静止,到达点O(尚在斜槽上)时相对圆盘的速度为v,试分析质点A在斜槽两端点C与点O处的非惯性系惯性力.
【单选题】There are many shops in Singapore where customers still bargain, although prices are clearly shown on the goods. There is nothing out of the ordinary in haggling some shopkeepers expect you to and wil...
A.
accepting the prices immediately
B.
fixing the right cost for some goods
C.
arguing about the price of something
D.
paying extra for comfortable shopping
【判断题】质量为m的质点A,在光滑的水平桌面上运动。在此质点上系着一根轻的绳子,绳子穿过桌面上的一个光滑小孔O,另一端挂一质量相同的质点B。若质点A在桌面上离O点为a的地方,沿垂直于OA的方向以速度【图片】射出,此质点在以后的运动中离O点的距离一定在a及3a之间。【图片】
【单选题】I bought six cows __________ we should have some milk to sell.
【单选题】下列成本、费用项目中属于产品完全成本但不属于产品变动成本的是() A.直接人工 B.按直线法计提的折旧费 C.财务费用 D.按产量法计算的折旧费
【简答题】对药品既有鉴别意义,又能反映药物纯度的检查项目是(___)。
【判断题】The number of units to be included in a study is called the sample size.
【单选题】在图中,质量为m的质点A,相对于半径为r的圆环作匀速圆周运动,速度为u;圆环绕O轴转动,在图示瞬时角速度为ω,角加速度为α。则图示瞬时,质点A的惯性力为______。
A.
F gx =m(2rα+2uω) F gy =m(2rω 2 +u 2 /r)
B.
F gx =-m(2rα+2uω) F gy =-m(2rω 2 +u 2 /r)