(10分)如图所示,一倾角为θ=37o的绝缘斜面高度为h=3m,底端有一固定挡板

题型:计算题

问题:

(10分)如图所示,一倾角为θ=37o的绝缘斜面高度为h=3m,底端有一固定挡板,整个斜面置于水平向右匀强电场中,场强E=1×106N/C.现有一质量为m=0.2kg,电荷量为q=-1×10-6C的小物体,沿斜面顶端从静止开始下滑,小物体与斜面间的动摩擦因数为µ=0.2,且小物体与挡板碰撞时不损失机械能(g=10m/s2,sin37o=0.6,cos37o=0.8)求:

(1)小物体第一次与挡板碰撞前瞬间的动能;

(2)小物体从静止开始下滑到最后停止运动通过的总路程s.

考点:带电粒子在复合场中的运动
题型:计算题

给下列多音字注音,再组词。

悄_____(  )  尽_____(  )  散_____(  )

 _____(  )   _____(  )   _____(  )

题型:计算题

炔雌醇环戊醚属于()

A.睾酮衍生物

B.孕酮衍生物

C.雌激素衍生物

D.FSH衍生物

E.GnRH衍生物

题型:计算题

维生素C的化学式为C6H8O6,下列关于维生素C的说法错误的是(  )

A.维生素C由C、H、O三种元素组成的

B.维生素C中,C、H、O三种元素的个数比为3:4:3

C.维生素C中,C、H、O三种元素的质量比为9:1:12

D.维生素C的相对分子质量为176

题型:计算题

It’s school time again! You’re probably feeling excited and maybe a little sad that summer is over. Some kids feel nervous or a little scared(害怕) on the first day of school because of all the new things: new teachers, new friends, and even a new school. Luckily, these “new” worries only stick around for a little while. Let’s find out more about going to a new school.

Most teachers kick off the new school year by introducing themselves and talking about all the stuff you’ll be doing that year. Some teachers give students a chance to tell something about themselves to the rest of the class, too. When teachers do the talking on the first day, they often go over classroom rules and school rules so you’ll know what’s allowed and what’s not. Please pay close attention

You might already know a lot of people in your classes on the first day, but it’s a great day to make a new friend, so try to say hello to kids you know and new ones that you don’t. Make the first move and you’ll be glad you did, and so will your new friend!

Seeing friends you haven’t seen for some time can make the first day a good one. You can make the day feel special by wearing clothes that you really like. Maybe you got a great T-shirt on one of your vacations, or a pair of sneakers(运动鞋). It also can make you feel good to be prepared and have all the things you need, such as pencils, folders, and whatever else you’ll be needing. But make sure that you pack them the night before in case you don’t have time in the morning.

小题1:The underlined phrase “kick off” in the second paragraph probably means “_____”.

A.start

B.study

C.find

D.teach小题2:The last paragraphs mainly tell us about ________.

A.what to know about a new school

B.how to prepare for a new school

C.what to do on your first day of school

D.how to spend your first day of school小题3:According to the passage you usually do everything on the first day of school except _______.

A.introduce yourself

B.learn about the school rules

C.make new friends

D.go over your new lessons小题4:If you happen to see an old friend on the first day of school, from the passage we know that you will feel ________

A.nervous

B.lucky

C.happy

D.excited

题型:计算题

在“图纸集特性”对话框中不可以设置图纸集的哪项特性()。

A.页面设置替代文件

B.用于创建图纸的样板文件

C.图纸集数据文件所在的位置

D.新创建图纸的保存位置

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