题目内容
如图所示,cd、ef是两根电阻不计的光滑金属轨道,其所在的平面与水平面间的夹角为600, 将两导轨用电键s相连,在两导轨间有垂直于导轨平面向上的匀强磁场,磁感应强度为B=0.5T,可在导轨上自由滑动的金属棒的长L=0.5m、质量为m=1.0
10![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140814975257.png)
kg,金属棒电阻为5Ω,设导轨足够长。(g=10m/s2)则:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241408151316566.jpg)
(1)若先将电键s断开,金属棒由静止开始释放后,经多长时间将s接通,ab恰作匀速运动?
(2)若先将电键s闭合,再将金属棒由静止释放,ab上的最大热功率为多大?
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140814912217.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140814975257.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140815022168.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241408151316566.jpg)
(1)若先将电键s断开,金属棒由静止开始释放后,经多长时间将s接通,ab恰作匀速运动?
(2)若先将电键s闭合,再将金属棒由静止释放,ab上的最大热功率为多大?
(1)0.8s(2)0.6W
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140815146511.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140815209486.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241408152561141.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140815302670.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140815349971.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140815396500.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241408155991190.png)
本题考查电磁感应与牛顿运动定律的结合,根据匀速运动受力平衡列式求解
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目