您所在的当前位置：初中数学试题 >

一元二次方程的应用

> 如图△ABC中，∠B=90°，点P从A点开始沿AB边向点B以1cm/s的速度匀速移动，点Q从B点开始沿BC边向点C以2cm/s的速度匀速移动． ①如果点P、Q分别从A、B同时出发，经过几秒钟，使△PBQ的面积为8cm 2？ ②如果点P、Q分别从A、B同时出发，经过几秒钟，使△PBQ与△ABC相似呢？

问题：

发布时间：2024-09-07

如图△ABC中，∠B=90°，点P从A点开始沿AB边向点B以1cm/s的速度匀速移动，点Q从B点开始沿BC边向点C以2cm/s的速度匀速移动．
①如果点P、Q分别从A、B同时出发，经过几秒钟，使△PBQ的面积为8cm ²？
②如果点P、Q分别从A、B同时出发，经过几秒钟，使△PBQ与△ABC相似呢？

参考答案：

提问用户：PF***Mc3

可能感兴趣的题目：

1 如图，点C是线段AB的黄金分割点（AC＞BC），下列结论错误的是 [ ] A. B.BC 2=AB·BC C. D.
2 如图，已知点E是圆O上的点， B、C分别是劣弧的三等分点，，则的度数为．
3 使得5×2 m+1是完全平方数的整数m的个数为______．
4 He was late for school, because he_____ the school bus. [ ] A. failed B. missed C. lost D. missing
5 我国公民享有基本的权利是指　　 [ ] A．成为国家主人的权利 B．法律确认的权利　　 C．行动自由的权利 D．我国宪法规定的公民权利
6 It was June. The sun was in the sky. It was very hot. Jim was tired of school. He wanted to be at the beach. He could not stay in his 1 . He could not 2 talking. While the teacher wrote on the board, Jim got up and talked to a friend. The teacher, Mr Smith, heard the 3 and said: "Jim, sit down and be quiet. " Jim sat down. Mr Smith 4 his lesson. Jim got up and talked to another friend. "Sit down and be quiet," said Mr Smith. He was very 5 . "OK," said Mr Smith. "If you want to talk, 6 come to the front of the classroom and 7 the teacher. " "All right," 8 Jim. He came to the front of the classroom and said:"Quiet, 9 . I am the new teacher. Class is over now. Let"s have a 10 " 小题1: A．office B．home C．seat D．room 小题2: A．stop B．enjoy C．forget D．finish 小题3: A．news B．story C．fact D．noise 小题4: A．got ready for B．went on with C．went over D．was interested in 小题5: A．angry B．sad C．worried D．afraid 小题6: A．again B．also C．then D．next 小题7: A．hear B．find C．ask D．be 小题8: A．asked B．agreed C．guessed D．laughed 小题9: A．anyone B．someone C．everyone D．no one 小题10: A．lesson B．break C．try D．meeting
7 元素周期表是我们学习化学的重要工具．下图中的①、②是氟元素、钙元素在元素周期表中的信息，A、B、C、D是某四种粒子的结构示意图．请回答下列问题：（1）钙元素的原子序数为______；（2）粒子 A、B、C、D中，属于同种元素的粒子是______；（3）B、C、D中与A粒子的化学性质相似的粒子是______．
8 从19世纪60年代——20世纪初，中国人民进行了近代化的探索，请举出与之有关的四大事件，并分别指出其主要目标。
9 阅读并回答问题。寓言四则　　蚂蚁要搬大象　　蚁巢里出现了罕有的大饥荒，一时间，蚁心惶惶。　　蚁巢里的匆匆大将军立即挺身而出，登高振臂而呼：“同胞们!你们都听说过，世上有一种巨大的动物叫大象吧?大伙别急，我们窝外就有一头大象，大伙跟我出去把它搬回来，管保我们一百年都不会缺粮!” 　　在匆匆大将军的___________下，头脑发热的群蚁几乎倾巢而出，浩浩荡荡跟随匆匆大将军去搬大象。只有一只蚂蚁没随大流，他独自出发去找一粒小米。　　这只蚂蚁深知，一粒实实在在的小米，比一个巨大而虚幻的理想更管用。　　占窝鸡　　花母鸡早巳无蛋可下，却总在黑母鸡要下蛋之前抢占了鸡窝，不让黑母鸡进入。　　黑母鸡忍无可忍，就同花母鸡理论。　　没想到花母鸡___________地说：“下蛋是每只母鸡天赋的神圣权利和义务，难道你要剥夺我的这份权利和义务?告诉你，这会儿我是无蛋可下，但这并不能说明过会儿我也无蛋可下。要是不让我蹲窝，蛋下出来摔破了你能负责?”花母鸡说罢，继续心安理得地趴在窝里。　　可怜有蛋的黑母鸡，被憋得在窝外团团乱转…… 　　蜗牛争名　　一只蜗牛爬到农民脚边，探头探脑质问农民：“我的名字里也有个牛字，你们为什么不给我牛的荣誉，牛的地位，牛的礼遇?” 　　农民笑呵呵地说：“好啊，蜗牛先生，我们可以给你所要的一切。可为了让你___________，还是先请你下田来拉拉犁吧!” 　　蜗牛灰溜溜地逃走了。　　生活　　涨水了，浮萍随水四处漂散，浮萍说：“跟着感觉走。” 　　起风了，灰尘凭风纷纷扬扬，灰尘说：“轻轻松松过一生。” 　　云在碧空里悠游，无忧无虑无牵无挂，云说：“何不潇洒走一回。” 　　田野里，一头牛在躬耕：埋着头，倾着身躯，鼓凸着肌腱。牛说：“活着，就___________忘记肩上的责任。” 1．从下面词语中选择恰当的填人各则寓言的横线上。鼓励　理直气壮　不会　认真　坦率　名副其实　鼓动　不该　尝尝滋味依次填：___________、___________、___________、___________ 2．“蜗牛”与“耕牛”都是“牛”，本质上有什么不同？ _________________________________________________________ 3．从“自不量力”、“愚公移山”两个成语中选择一个填入下句。区区蚂蚁想把大象搬回洞里，真可谓___________。 4．《生活》运用___________的写法，把___________作为歌颂对象。 5．把有关内容用直线连接起来。《蚂蚁要搬大象》　　　　　　　A．讽刺了不做实际工作还强词夺理的人。《占鸡窝》　　　　　　　　　　B．不讲奉献，永远得不到人们的尊重。《蜗牛争名》　　　　　　　　　C．抛却不切实际的幻想，提倡务实精神。《生活》　　　　　　　　　　　D．人生应该有目标，并为之努力奋斗。
10 根据下面短文内容，在短文的空格处填上一个恰当的词，使短文完整、通顺。 Whenever we see something new, we wish to write it down in one form or another. We will be happier if we share (分享) our experience with others. Then 1 can we write better travel stories? The following may be helpful. Memory and notes Don"t believe your memory. You may have a good memory, 2 you cannot remember everything. You are seeing and hearing so much information while you"re on a trip. When you return to write about your travel stories, you may forget something. So you should make notes, take photographs, and if 3 , take videos. In this way, you can describe your travel and write it down 4 missing anything. Photographs and your stories Photographs are very useful for you to remember what you have seen. As you see the photographs, you can describe your experiences easily by remembering how you felt when you took 5 . When you are writing about your travel stories, make sure they are not too short as your reader may not get the full impression (印象) of them and make sure they are not so 6 that the reader may get bored. Popular factors (因素) Make sure your stories have popular factors and the reader will find your travel stories not only pleasant to 7 , but useful as well. Popular factors are food to eat, places to stay and the things to look out for while 8 . They should also include what you"ve found useful and the things you miss so much.