问题
计算题
如图所示，A、B质量之比mA：mB=5：3，它们与水平面间的动摩擦因数相等，在水平推力F作用下向右匀速运动，求B对A的作用力大小。
答案
解：以A、B整体为研究对象：F=μ(mA+mB)g
隔离B：FAB=μmBg
所以
根据牛顿第三定律，B对A的作用力
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如图所示，A、B质量之比mA：mB=5：3，它们与水平面间的动摩擦因数相等，在水平推力F作用下向右匀速运动，求B对A的作用力大小。
解：以A、B整体为研究对象：F=μ(mA+mB)g
隔离B：FAB=μmBg
所以
根据牛顿第三定律，B对A的作用力
| 阅读理解。 | ||||||||||||||||||||
The following form shows some CCTV shows.
| ||||||||||||||||||||
| 1. Who are the hosts of News Broadcast of CCTV-1? | ||||||||||||||||||||
| A. Zhang Hongmin and Li Zimeng. B. Ouyang Zhiwei. C. Liu Ye and Bian Ce. D. Dong Yi. | ||||||||||||||||||||
| 2. When can we watch The First Time on Sunday? | ||||||||||||||||||||
| A. At 19:00—19:30. B. At 7:00—9:00. C. At 9:00—10:00. D. At 19: 10. | ||||||||||||||||||||
| 3. If we want to learn something about movies, we can watch ______. | ||||||||||||||||||||
| A. CCTV-1 B. CCTV-2 C. CCTV-6 D. CCTV-11 | ||||||||||||||||||||
| 4. The TV show Dong Yi hosts is ______. | ||||||||||||||||||||
| A. News Broadcast B. The First Time C. The World Movie Trip D. Learn after Me | ||||||||||||||||||||
| 5. Which of the following is NOT true? | ||||||||||||||||||||
| A. Ouyang Zhiwei is one of the hosts of CCTV-2. B. Dong Yi is one of the hosts of CCTV-6. C. Te can watch The World Movie Trip every day. D. We can watch Learn after Me three times every week. |
