如图所示，导体棒ab长0.5m，质量为0.1kg，电阻R=5.5Ω，电源的电动势E=3V，r=0.5Ω，整个装置放在一磁感应强度B=2T的磁场中，磁场方向与导体棒垂直且与水平导轨平面成53°角，导体棒静止．求：导体棒受到的摩擦力和支持力（不计导轨电阻）．（sin53°=0.8）
通过导体棒的电流 I=
=E R+r
A=0.5A3 5.5+0.5
导体棒受到的安培F=BIL=2×0.5×0.5N=0.5N
由受力分析f=Fsinθ=0.4N，
水平向右N=mg+Fcosθ=1.3N，竖直向上．
| 完形填空。阅读下列短文，从所给的四个选项中选出最佳答案。 | ||||
| A young man once asked Albert Einstein, the great scientist, 1 the secret of success(成功) is. The scientist told him that the secret of success is 2 work. A few days later the young man asked him the same question again. Einstein was very 3 . He did not say 4 , but wrote 5 words on a piece of paper and handed it 6 the young man. The young man looked at the piece of paper. 7 it was written: A=X+Y+Z. "What does this 8 ?" asked the young man. "A means success," 9 the old scientist. "X stands for(代表) hard work, Y stands for good methods(方法)  , and Z…,Z means stopping 10 and getting down to work." | ||||
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