一弹簧振子振动过程中的某段时间内其加速度数值越来越大，则在这段时间内（ ）
A．振子的速度逐渐增大
B．振子正在向平衡位置运动
C．振子的速度方向与加速度方向一致
D．振子的位移逐渐增大
答案：D
题目分析：，弹簧振子振动过程中，加速度数值越来越大，位移数值越来越大，振子离开平衡位置，速度越来越小．AB错误，D正确，由上分析可知，振子正离开平衡位置，速度方向离开平衡位置，加速度方向指向平衡位置，所以振子的速度方向与加速度方向相反．故C错误．
点评：根据弹簧振子的加速度与位移成正比，由加速度的变化分析位移的变化．当振子的位移增大时，振子离开平衡位置，速度减小，加速度方向与速度方向相反；当振子的位移减小时，振子向平衡位置靠近，速度增大，加速度方向与速度相同．
| A few years ago, my friend Al won the lottery ( * * ), which changed his life. He was not born with a silver spoon in his mouth. 1 , my friend was always hard up for cash. He did not have much money. And the money he did earn was chicken feed - very 2 . Sometimes Al even had to 3 some gifts from his family and friends. He was not the kind of person who never paid the money he 4 .He was always very careful with the money he spent. The 5 times were when he was flat broke and had no money at all. One day, Al scraped together a few dollars for a 6 ticket. He thought he would never gain lots of money 7 . But his combination of numbers was chosen and he 8 the lottery. That is to say, he won a great deal of 9 . Al was so 10 . The first thing he did was to buy a new car. He showed off the one thing that he normally would not buy. Then he started spending money on 11 things. It was like he had money to 12 . He had more money than he needed and it was burning a hole in his pocket so he spent it quickly. When we 13 for a meal at a restaurant, Al paid every time. He would always pay bills for others. He told me the money made him feel like a millionaire 14 he felt very happy. But shortly after that my friend was 15 and out again. He had no money left. He had 16 his bottom dollar, his very last amount. I admit I do feel 17 for my friend. He had enough money to live like a king. Instead, he is 18 to living on a shoestring - a very low budget. Some might say he is penny 19 and pound foolish. He was wise about small things, but 20 about important things. | ||||
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