题干

 为了深入推进“美丽南宁,整洁畅通有序大行动”,南宁市公安交警部门于2015年3月至年底,在全市范围集中开展电动自行车交通违法专项整治行动.其中,禁止电动自行车“超载”、“超速”.请运用所学的物理知识说明这两个规定的道理.

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答:从惯性的角度,“超载”时电动自行车的质量大,惯性大,刹车时不易刹住.同时,刹车时若电动自行车“超速”,则由于惯性要保持原来的速度,使刹车的距离变长,容易造成危险;

从动能的角度,电动自行车“超载”、“超速”会使其质量变大、速度变大,动能增大,一旦发生交通事故其伤害也会更大.

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    While music has value all by itself, researchers have long noticed that musicians also tend to be better at learning languages and show other improved reading and math abilities. Now a new study from the University of Washington by Christina Zhao shows that rhythm is an important bridge between music and speech as early as nine months of age.

    Researchers randomly placed babies into two groups of 20 each, and each group played at the lab with their parents for a dozen 15-minute sessions over a month.

    In one group, researchers played recordings of songs with a waltz rhythm and showed the parents how to help their babies tap out that 1-2-3 beat in time with the music on boy drums or with their feet. In the other group, children played with typical toys and no music.

    The babies in the music group were better able to detect random mistakes in that rhythm when they heard it within two weeks of the last session. They also showed a stronger brain response to disruptions in the rhythm. For example, researchers would sometimes alter the timing of syllables(音节) by slightly shortening the middle sound of a word like bibbi to make it bibi—and the babies with music training were more likely to notice it.

    In other words, music training not only improved the babies' ability to notice when a musical rhythm skipped a beat, but also improved their ability to notice when the rhythms of speech changed unexpectedly, an important skill for learning to talk.

    The study reflects Zhao's personal experiences as a pianist who music in college, and as someone who speaks both Mandarin and English. She noticed that a lot of her fellow musicians were also good at learning other languages. “That really got me wondering how these two are related, “Zhao said.

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