求解答，要过程，谢谢。_百度知道
求解答，要过程，谢谢。
一平行板电容器半场L=4cm,板间距离为d=3cm,倾斜放置，使板面与水平方向夹角α=37°，若两板间所加电压U=100v，一带电荷量q=3×10的负十次方库的负电荷一V0=0.5m/s的速度自A板左边缘水平进入电场，在电场中沿水平方向运动，恰好从B板右边水平飞出，则带电粒子从电场中飞出速度为多少？带电粒子质量为多少？
提问者采纳
带电粒子做直线运动，在竖直方向有：qU/dcos37°＝mg
所以m=8×10^-8kg带电粒子所受合力与电场力在水平方向的分力相同，F合=qEsin37°=6×10^-7N再由动能定理有：F合×L/cos37=mv^2/2-mvo^2/2
额，请问mv^2/2-mvo^2/2是什么意思，我没看懂，谢谢。
末动能减初动能。动能定理，合外力做的功，等于动能的变化。
提问者评价
原来是这样，感谢！
其他类似问题
为您推荐：
等待您来回答
下载知道APP
随时随地咨询
出门在外也不愁求解答过程：阅读下面的文字，按要_百度知道
求解答过程：阅读下面的文字，按要
阅读下面的文字，按要求回答1～5小题。 　　（甲）山不在高，有仙则名。水不在深，有龙则灵．斯是陋室，惟吾德馨。苔痕上阶绿，草色入帘青。谈笑有鸿儒，往来无白丁。可以调素琴，阅金经。无丝竹之乱耳，无案牍之劳形。
南阳诸葛庐，西蜀子云亭
。孔子云：何陋之有？（选自刘禹锡《陋室铭》） 　　（乙）赵襄主学御于王于期。俄而与于期逐，三易马而三后。 　　襄主日：“子之教我御，术未尽也。”对日术已尽用之则过也。凡御之所贵，马体安于车；人心调于马，而后可以进速致远。今君后则欲逮臣，先则恐逮于臣。夫诱道争远，非先则后也。而先后心毕在于臣，上何以调于马？此君之所以后也。”（选自《韩非子?喻老》）
1．下列句子中，加粗词语的解释不正确的一项是 A．
吾德馨：只 &&&& B．谈笑有鸿
：旧指读书人 &&&& C．可以
素琴：协调 &&&& D．无丝竹之
耳：使……乱，扰乱
2．选文中画线语句运用了什么论证方法？有什么作用？ ______________________________________________________ 3．请概括选文的主旨（用原文的语句回答）。 ______________________________________________________
4．用“／”给下句断句。& 对日术已尽用之则过也 ______________________________________________________&
5．用现代汉语翻译下面的句子。&& ①俄而与于期逐，三易马而三后。 ______________________________________________________
②子之教我御，术未尽也。 ______________________________________________________&
我有更好的答案
1．C&& 2．举例论证，作者以故仁人自况。（答对1问给1分，两问都答对给满分）。&& 3．斯是陋室，惟吾德馨。&& 4．对曰／术已尽／用之则过也&&&& 5．（1）过了一段时间（小久），（赵襄主）就跟王于期赛马，他多次换马多次都落后。& 　 （2）你教我驾驭车马的方法（技术）没有全部教给我。
其他类似问题
为您推荐：
阅读下面的相关知识
等待您来回答
下载知道APP
随时随地咨询
出门在外也不愁求解答过程：This is for you!_百度知道
求解答过程：This is for you!
This is for you!
A. Wow! Thank you. B. Let's go to school!
我有更好的答案
其他类似问题
为您推荐：
等待您来回答
下载知道APP
随时随地咨询
出门在外也不愁求解答过程：阅读下面的文章，完成_百度知道
求解答过程：阅读下面的文章，完成
阅读下面的文章，完成问题。
人是一根能思想的苇草
　　我很能想象一个人没有手、没有脚、没有头（因为只是经验才教导我们说，头比脚更为必要）。然而，我不能想象人没有思想，那就成了一块顽石或者一头畜牲了。 　　思想形成人的伟大。 　　人只不过是一根苇草，是自然界最脆弱的东西，但他是一根能思想的苇草。用不着整个宇宙都拿起武器来才能毁灭他，一口气、一滴水就足以致他死命了。然而，纵使宇宙毁灭了他，人却仍然要比致他于死命的东西高贵得多，因为他知道自己要死亡，以及宇宙对他所具有的优势，而宇宙时此却是一无所知。 　　因而，我们全部的尊严就在于思想。正是由于它而不是由于我们所无法填充的空间和时间，我们才必须提高自己。因此，我们要努力好好地思想。这就是道德的原则。 　　能思想的苇草——我应该追求自己的尊严，绝不是求之于空间，而是求之于自己思想的规定。我占有多少土地都不会有用，由于空间，宇宙便囊括了我并吞没了我，有如一个质点；由于思想，我却囊括了宇宙。
1．在文章的第一段中，作者为什么说“我不能想象人没有思想”？
_____________________________________________ 2．文章中说：“我们全部的尊严就在于思想。正是由于它而不是由于我们所无法填充的空间和时间，我们才必须提高自己。”请对这句话加以解释。
_____________________________________________ 3．文章结尾说：“我占有多少土地都不会有用，由于空间，宇宙便囊括了我并吞没了我，有如一个质点；由子思想，我却囊括了宇宙。”请对这句话加以解释。
_____________________________________________ 4．阅读全文，然后概括这篇文章的主旨。
_____________________________________________
我有更好的答案
1．因为人只要还有思想，就还是人；没有了思想，就无法同自然界的万物区分开了。
2．人有一种希望，就是填充空间和时间，即希望自己占有更大的空间和时间。但与浩瀚的宇宙相比，人占有多少空间都没有用；人无法避免死，因此也占不了多长时间。人的尊严不在于填充空间和时间，而在于思想。思想有深浅高低之分，高明的、有深度的思想才能使人获得力量，体现出人发展自己、完善自己的力量，显示出人的特性和魅力，也即获得人在自然万物中的“尊严”。因此要“努力好好地思想”“提高自己”。
3．人无法填充空间和时间，在空间无限大的宇宙面前，人显得微不足道。但人有思想，思想是没有边界、不受限制的，它可以把整个宇宙作为思考的对象，从这个意义上说，人囊括了宇宙。
4．人本身很脆弱，伟大之处在于能思想，人应该“努力好好地思想”。（意对即可）
其他类似问题
为您推荐：
阅读下面的相关知识
等待您来回答
下载知道APP
随时随地咨询
出门在外也不愁求解答过程：阅读理解。 O_百度知道
求解答过程：阅读理解。 O
阅读理解。
&&& One day, Jack's parents told him that his grandpa would retire (退休) after working forty years. Jack said in surprise, "I'm only seven, so it means Grandpa has been…er…A really long time!"
&&& His parents said, "Yes. That's why we are going to have a surprise party for him."
&&& Jack loved his Grandpa and wanted to do something special for him. He remembered the business card his grandpa had given him two years before. He knew that his grandpa would no longer have the position
(职位) on that card, so he decided to build a new one for his grandpa.
&&& When the big day came, Jack was ready. But he didn't want to put his gift together with other's. He
carried it around with him the whole evening.
&&& When all the other people left, he took his grandpa's hand and brought him over to a chair and gave him a gift.
&&& His grandpa smiled, "Well, it must be a beautiful gift. May I open it now?" "Sure!" Jack said excitedly.
&&& As grandpa opened the gift, tears (眼泪) came into his eyes. Jack gave him the greatest gift he had never got! They were business cards with his new position: FULL-TIME GRANDPA! Jack said, "Now your full-time job is my grandpa!"
&&& "well, how much do I get paid?" his grandpa asked, smiling, "As many hugs (拥抱) as you want!" With these words, Jack gave Grandpa a hug. "Well, I guess that means I'm the richest man in the world!" said
1. Who was going to retire?
A. Jack's grandma
B. Jack's grandpa C. Jack'd mother
D. Jack's father
2. What remembered ______ his grandpa had given him two years before?
A. the birthday card
B. the boy
C. the book D. the business card
3. What did Jack decide to do for his grandpa?
A. To build a new position for him B. To draw a picture for him
C. To sing a song for him
D. To buy a gift for him
4. Which of the following is true?
A. Jack was the first one to give his gift to his grandpa
B. Jack was the last one to give his gift to his grandpa
C. Jack gave his gift to his grandpa together with other people
D. Jack gave his gift to his grandpa together with his parents
5. Why were there tears in grandpa's eyes?
A. Because he would lost his position
B. Because he was not cared for C. Because he was moved by Jack's gift
D. Because he was unhappy
我有更好的答案
1-5: BDABC
其他类似问题
为您推荐：
阅读理解的相关知识
等待您来回答
下载知道APP
随时随地咨询
出门在外也不愁