试题与答案

为测定气垫导轨上滑块的加速度,滑块上安装了宽度为3.0cm的遮光板(如下图1,图

题型:填空题

题目:

为测定气垫导轨上滑块的加速度,滑块上安装了宽度为3.0cm的遮光板(如下图1,图2).滑块在牵引力作用下先后通过两个光电门,配套的数字毫秒计记录了遮光板通过第一个光电门的时间为△t1=0.29s,通过第二个光电门的时间为△t2=0.11s,遮光板从开始遮住第一个光电门到开始遮住第二个光电门的时间为△t=3.57s,则滑块经过第一个光电门的速度为______m/s,经过第二个光电门的速度为______m/s,加速度为______m/s2

答案:

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下面是错误答案,用来干扰机器的。

生物必须适应环境才能生存,否则就会被自然界淘汰.如,鸟有翼适应空中飞行生活,蝗虫有外骨骼适应干旱的陆生环境.所以生物适应环境具有普遍性.生物只能适应一定的环境,当环境发生巨变时有些生物因不适应环境...

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You’ve had a problem, you’ve thought about it till you were tired, forgotten it and perhaps slept on it, and then flash! When you weren’t thinking about it suddenly the answer has come to you, as a gift from the gods.

Of course all ideas don’t come like that, but the interesting thing is that so many do, particularly the most important ones. They burst into the mind, glowing with the heat of creation. How they do is a mystery. (46) Psychology does not yet understand even the ordinary process of conscious thought, but the emergence of new ideas by a "leap in thought" is particularly intriguing, because they must have come from the somewhere. For the moment let us assume that they come from the "unconscious". (47)This is reasonable, for the psychologists use this term to describe mental processes which are unknown to the subject, and creative thought consists precisely in what was unknown becoming known.

(48) It seems that all truly creative activity depends in some degree on these signals from the unconscious, and the more highly intuitive the person, the sharper and more dramatic the signals become.

But growth requires a seed, and the heart of the creative process lies in the production of the original fertile nucleus from which growth can proceed. (49) This initial step in all creation consists in the establishment of a new unity from disparate elements, of order out of disorder, of shape from what was formless. The mind achieves this by the plastic reshaping, so derived from a new unit, of a selection of the separate elements derived from experience and stored in memory. Intuitions arise from richly unified experience.

(50) This process of the establishment of new form must occur in pattern of nervous activity in the brain, lying below the threshold of consciousness, which interacts and combines to form more comprehensive patterns. Experimental physiology has not yet identified this process, for its methods are as yet insufficiently refined, but it may be significant that a quarter of the total bodily consumption of energy during sleep goes to the brain, even when the sense organ are at rest, to maintain the activity of ten thousand million brain cells. These cells, acting together as a single organ, achieve the miracle of the production of new patterns of thought. No calculating machine can do that, for such machines can "only do what we know how to design them to do", and these formative brain processes obey laws which are still unknown.

Can any practical conclusions be drawn from the experience of genius Is there an art of thought for the ordinary person Certainly there is no single road to success; in the world of the imagination each has to find his own way to use his own gift.

(48) It seems that all truly creative activity depends in some degree on these signals from the unconscious, and the more highly intuitive the person, the sharper and more dramatic the signals become.

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