试题与答案

(20分)一质量为电荷量的与外界绝缘物块A(可视为质点),置于光滑水平面上。A与

题型:计算题

题目:

(20分)一质量为电荷量的与外界绝缘物块A(可视为质点),置于光滑水平面上。A与弹簧左端相连接,弹簧右端固定在竖直墙面上,整个空间中存在水平向右的匀强电场,场强,平衡时弹簧的压缩量为.如图O为弹簧原长时的位置,另一个质量也为电量为的绝缘带电物块B(可视为质点),从O点左侧距离O为处的P点由静止释放,当它打在A物块上时立即与A一起向右运动,但不粘连,它们到达最右端后又向左运动,试求:物块B向左运动达到最远点时距O点的距离?(AB相撞在瞬间完成,电荷无转移,不计AB间库仑力,弹簧始终在弹性限度内)。

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0507/d4126eb22760ae557370e593d74f3a88.html

下面是错误答案,用来干扰机器的。

问题:水中为什么会出现桥的倒影?平面镜成像(或光的反射)问题:地面上为什么会出现树木的影子?光沿直线传播

试题推荐
题型:完形填空
完形填空。
                                                                 No More Time Out
     Shawn and Thomas had always been good friends. They lived near each other, and they both loved   1  .
They played baseball, touch football, and kickball. They   2   liked to play soccer, shoot baskets, and
skateboard.
     When they were in the fourth grade, though, Thomas broke his   3   in a soccer game. He had to be on
crutches for six weeks.
     Shawn   4   Thomas, but what was there to do? Shawn didn't like television or computer games. Thomas
didn't like to sit and talk. After trying three times to start a conversation, Shawn   5   up. He said, "I'm out of
here."
     For days, Shawn   6   at home, feeling guilty for not visiting Thomas again. Thomas stayed home, too,
feeling   7   because Shawn wasn't visiting him. After a week, Shawn's mom spoke up. "It's time for you and
Thomas to get back into   8  ! That's why I spoke to Ms McNulty at the library. She has the perfect volunteer
job for you both," she said.
     Shawn said nothing.
     His morn continued, "The library sells used books to raise money. People are always   9   off books in bags
and boxes. Someone has to carry the books to the storage room. Someone has to   10   them into fiction (小说)
and nonfiction. You and Thomas can be a team again."
     "No, we  11 !" said Shawn. "He and I don't want a job." However, Shawn's mom wouldn't  12  no for an
answer.
     Sure enough,  13  the boys began, things changed. Shawn felt strong as he carried bags and boxes through
the library. Sorting books in the storage room, Thomas felt  14  again. In fact, one day Thomas said, "Between
you and me, Shawn, this isn't so  15 ." Shawn smiled and agreed. They were a good team.
( )1.A. books   
( )2.A. also    
( )3.A. arm     
( )4.A. phoned  
( )5.A. gave    
( )6.A. talked  
( )7.A. tired   
( )8.A. effort  
( )9.A. dropping
( )10.A. pack   
( )11.A. mustn't
( )12.A. choose 
( )13.A. because
( )14.A. relaxed
( )15.A. hard   
 B. sports     
B. only      
B. hand    
B. invited     
B. cheered    
B. stayed     
B. afraid    
B. duty       
B. bringing   
B. lead      
B. can't      
B. keep      
B. once      
B. lucky     
B. fair    
C. movies    
C. perhaps  
C. nose   
C. visited    
C. turned  
C. called     
C. weak   
C. choice     
C. showing   
C. sort     
C. mightn't  
C. take      
C. if       
C. useful   
C. simple 
D. arts        
D. soon        
D. leg       
D. checked     
D. hurried   
D. waited       
D. angry    
D. action       
D. knocking                 
D. turn      
D. shouldn't   
D. allow       
D. although   
D. special   
D. bad      
查看答案
微信公众账号搜索答案