问题
不定项选择
如图所示,将完全相同的两个小球A、B,用长L=0.8m的细绳悬于以v=4m/s向右匀速运动的小车顶部,两球与小车前后壁接触,由于某种原因,小车突然停止运动,此时悬线的拉力之比FB∶FA为(g=10m/s2)

A.1∶1
B.1∶2
C.1∶3
D.1∶4
答案
答案:C
如图所示,将完全相同的两个小球A、B,用长L=0.8m的细绳悬于以v=4m/s向右匀速运动的小车顶部,两球与小车前后壁接触,由于某种原因,小车突然停止运动,此时悬线的拉力之比FB∶FA为(g=10m/s2)
A.1∶1
B.1∶2
C.1∶3
D.1∶4
答案:C
选用方框中单词的适当形式完成对话。 | |
B: (2)______, please! I want (3)______ the Japanese club. A: Good! (4)______ I know (5)______ name? B: Robert. A. Robert. Yes, I got it. And (6)______ is your family name? B: White. A: (7)______ old are you? B: Thirteen. A: Can you (8)______ Japanese? B: Yes, but (9)______ very well. I want to learn more (10)______ it. A: OK! Do you have an (11)______ address? B: Yes, it's Robert@ 126. com. cn. A: Great! Thanks a (12)______. |