质点沿直线运动的运动学方程为x=2+6t-t2(SI)，则质点速度为零时X等于( )-湖北继续教育网网校

首页

普通专升本

成人高考

学位英语

在线刷题

最近学习

最近学习课程

最强大脑 · 3天挑战极限记...

副标题副标题副标题副
最强大脑 · 3天挑战极限记...

副标题副标题副标题副

您现在位置：模拟考场> 湖北自学考试> 专业课> 物理（工）> 浏览试题

[单选题]质点沿直线运动的运动学方程为x=2+6t-t2(SI)，则质点速度为零时X等于( )

A1lm

B10m

C9m

D8m

收藏查看答案

相关题目

热门试题

1. 24．1935 年 12 月，中共中央召开的确定抗日民族统一战线政策的会议是
2. 改造资本主义工商业和逐步完成社会主义过渡的必经之路是（　　）
3. 一、单项选择题(本大题共25小题，每小题l分，共25分) 在每小题列出的四个备选项中只有一个是符合题目要求的，请将其选出并将“答题卡”的相应代码涂黑。错涂、多涂或未涂均无分。 1、世界公认的第一台机械电视机的发明人是
4. can kill your dream. ( ) 查看材料
5. Passage ThreeWhat exactly is a lie? Is it anything we say which we know is untrue? Or is it something more than that? For example, suppose a friend wants to borrow some money from you, you say "I wish I could help you but I'm short of money myself." In fact, you are not short of money but your friend is in the habit of not paying his debts and you don't want to hurt his feeling by reminding him of this.Is this really a lie?Professor Jerald Jellison of the University of Southern California has made a scientific study of lying.According to him, women are better liars than men, particularly when telling a "white lie".For instance, when a woman at a party tells another woman that she likes her dress, she really thinks it looks awful.However, this is only one side of the story. Other researchers say that men are more likely to tell more serious lies, such as making a promise which they have no intention of fulfilling.This is the kind of lie politicians and businessmen are supposed to be particularly skilled at: the lie from which the liar hopes to profit or gain in some way.Research has also been done into the way people's behavior changes in a number of small,apparently unimportant ways when they lie. It has been found that if they are sitting down at the time, they tend to move about in their chairs more than usual.To the trained observer they are saying "I wish I were somewhere else now" .They also tend to touch certain parts of the face more often, in particular the nose.One explanation of this may be that lying causes a slight increase in blood pressure.The tip of the nose is very sensitive to such changes and the increased pressure makes it itch.Another gesture which gives liars away is what the writer Desmond Morris in his book Man-watching calls "the mouth cover". He says there are several typical forms of this, such as covering part of the mouth with the fingers, touching the upper-lip or putting the hand at one side of the mouth.Such a gesture can be understood as an unconscious attempt on the part of the liar to stop himself or herself from lying.Of course, such gestures as rubbing the nose or covering the mouth or moving about in a chair cannot be taken as proof that the speaker is lying. They simply tend to occur more frequently in this situation.It is not one gesture alone that gives the liar away but a whole number of things, and in particular the context in which the lie is told.31.According to the passage, a "white lie" seems to be a lie (　　).A.that other people believeB.that other people don't believeC.told in order to avoid offending someoneD.told in order to take advantage of someone

热门试卷