2022英语周报gc42答案

答案】D解析】【分积本题主要是考查了共点力的平衡问题,解答本题的关键是:确定研究对象、进行受力分析、根据衡条件建立平衡方程进行解答。注意整体法和隔离法的应为研究对象,根据平衡条件求解水平状态时拉力F大小,利用作析F的变化情况的拉力大斜面和A物体为研究对象,水平方向受力平衡分析地面对斜面的摩擦力大小的变化:对A进行分析,根据连接A绳子的拉力变化情况分析A受到的庠擦力的变化情A以结点O为研究对象子拉力,如图所示设B的质量为m,水平状态时拉力F=mgta60°=mg保持点的位置不变,沿顺时针方向缓慢调整力F的方向直至竖直,由图可知,F先减小后增大在竖直方向时,根据平衡条件可知F=m9,故拉力F的大小不可能与水平状态时的值札B由图可知,物块A所受细绳的拉力大C以斜面和A物体为研究对象,地面对斜面的摩擦力大小f=Tin60直减小,所减小,故C锴D如果A开始受到的摩擦力方向沿斜面向下,则绳子拉力T减小到零的过程中,物块A所受斜面

第三节One possible wersionParagraph 1Some time later, he woke up under a tree in the samevalley. He was alone, worried about his dog and he knewhe was going to get into more trouble with his wife. Then henoticed a curious thing his hair was over his shouldersand his beard was over a foot long! So strange was he thathe decided immediately to get back to the village. As soonas he got there, he realized that everything was differentand there were lots of new houses. Surprisingly, he didn'trecognize the people in the villageParagraph 2:When he got to his house, he saw that it was old andbandoned. To his sorrow, his wife had died two years before and the two children had left away. Despite the arment with his wife, he was regretful for the past. Facingthis sharp change, Rip was determined to change his way ofliving and never be a lazy man. He became a diligentfarmer and kept pace with the new society. In his sparetime, he would still go to the old inn that had been rebuiltto tell some stories about his adventure in the valley, whichappealedto the children a lo

以上就是2022英语周报gc42答案，更多英语周报答案请关注本网站。