某汽车在高速公路上直线行驶，刹车后汽车的速度为，求刹车后汽车前进（ ）米才能停住。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/ae3a480bc5e54326af56887c76f74ca0.png
举一反三
- 汽车以十米每秒的速度在公路上匀速行驶,刹车后经两秒速度变为六米每秒,求；刹车后两秒内前进的距离,与刹车过程中的加速度,刹车后前进九米所用的时间
- 以72km/h的速度在平直公路上行驶的汽车，遇紧急情况而急刹车获得大小为4m/s2的加速度，则刹车3s后汽车的速度和刹车7s后汽车的速度分别是多少？
- 拉普拉斯（Laplace）方程的表达式为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/26731bcad75f41389448b29292940653.jpg" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/40e7e55a72ee44f59b45d20c84ebe3a6.jpg" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/c65a79ea4d754174b99f34020d6e1735.jpg" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/139e8d3dc37941549e7b6b1731243172.jpg" />
- 平面一维稳定渗流的压力分布公式为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/d08348f3b84f442d87994311dc13686b.jpg" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/2df214c86c5e4103897ba81ce2c6cd98.jpg" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/cc98e4a778cc463c965ac8115e028f86.jpg" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/bc82177c19d44acfa1b365c3d66ed0a4.jpg" />
- 一质点在平面上作一般曲线运动，其瞬时速度为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/072ecbf2079c40debf10e59602baef5a.png" />，瞬时速率为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/a7c386a2ed9641fb872fd3798d8a18d6.png" />，某一段时间内的平均速度为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/fd7b24d84b0c48b29b905c0accbfb682.png" />，平均速率为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/25c97028c3294855859e6d26731aecd6.png" />，它们之间的关系必定有（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/28eb779628f849cb9c561087ac27668c.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/332a22fc817749108da3ea994f11c24e.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/9fee0e92ea9344e18d11908ba83a7529.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/258f415ef0974549b35f450f710027de.png" />