您所在的当前位置：高中物理试题 >

匀变速直线运动

> 关于匀变速直线运动，下列说法中正确的是（　　） ①匀变速直线运动的运动轨迹是一条直线 ②匀变速直线运动的加速度的大小和方向均不变 ③匀变速直线运动的v-t图象是一条平行于时间轴的直线 ④匀变速直线运动的加速度大小是不变的，方向可以发生变化． A．①② B．③④ C．②③ D．①④

问题：

发布时间：2024-09-10

关于匀变速直线运动，下列说法中正确的是（　　）
①匀变速直线运动的运动轨迹是一条直线
②匀变速直线运动的加速度的大小和方向均不变
③匀变速直线运动的v-t图象是一条平行于时间轴的直线
④匀变速直线运动的加速度大小是不变的，方向可以发生变化．

A．①② B．③④ C．②③ D．①④

参考答案：

提问用户：3M***a2h

可能感兴趣的题目：

1 I met an old friend of ________ on my way ________ . A.my … home B.mine … home C.mine … to home D.me … to home
2 阅读下面的文字，完成后面的题目。山乡的五月金光　　天刚蒙蒙亮，根西就听见父亲窸窸窣窣地起了床，他翻了一个身又睡着了。这一觉他睡得好香，醒来已经是上午10点了，他洗了把脸，就坐在屋檐下看书。妈从灶房出来时说：“根西，去窑场地叫你大回来吃饭。”根西放下手中的书，朝窑场地走去。　　五月的山乡，到处都是金灿灿的颜色，田里熟透了的小麦散发出醉人的芳香。根西走在田埂上，看到了他童年的影子。18岁那年，在父亲的奔忙中，他从这里走出去，上了市技校，毕业后就到市一家化工厂当了一名化验员。根西走着走着，禁不住随手掐了一颗麦穗在手中揉搓起来，然后展开手掌用嘴一吹，留下一把嫩嫩的青麦，嘴一张嚼将起来。　　父亲正弯着腰在那里割麦，他的身后，已倒下去大片的麦子，裸露的地面上摆着整齐的麦铺。父亲手上的镰刀飞舞着，弄得周围一片呼呼啦啦的声响。　　“大，回家吃饭。”根西喊了一声。　　父亲根本没有听见，仍然在飞舞着镰刀割麦子，白色的汗衫已变得昏黄且湿漉漉地贴在了他的脊背上。　　“大，回去吃饭哩。”根西又叫了一声，嗓门比刚才高了些。　　“啊，喔，饭熟了？”父亲终于醒悟过来，缓缓地站起身，用肩膀上的毛巾擦了一把脸上的汗水。　　根西上前接下镰刀，父亲用极快的速度将两铺麦合在一起，扎了一捆就要往肩上扛。根西说：“我来拿吧。” 　　父亲说：“还是让我扛。小心弄脏了衣服。”说完扛起麦捆就走。根西用手拈掉沾在衣服上的一根麦芒，拿着镰刀跟在父亲的后面。　　饭桌上，根西对父亲说：“大，我看不如把咱那几亩地让给别人种去。” 　　“为啥？”父亲有点吃惊。　　根西木木地说：“不为啥，种田不划算，一年忙到头，一亩地就说打700斤麦子，6毛钱一斤才420块，抵不上在外干一个月的收入。” 　　父亲没有说话。　　根西又说：“你把地包出去，我到我们厂里给你找个临时活，一月能开500多块，行不？”父亲这才说：“娃，大是庄稼汉，一辈子跟土坷垃打交道，习惯了，没觉着受罪，我跟你妈在一起挺好，想家了你就回来看看我们。” 　　根西在家停了一周，父亲不让他沾庄稼的边儿，他是眼看着父亲割了麦再脱粒，然后扬麦、晒场，一点点将麦子弄回家里的。临走时，他无可奈何地摇了摇头。　　世上的事就这么不如意，两年后，根西所在的那家化工厂出现了意想不到的困境：化工原料价格猛增，化工产品却销不出去，全厂1000多名职工几个月发不下工资。厂里实在抵挡不住了，便痛下了改革的决心，决定减员增效，第一批减员百分之二十，根西首当其冲。　　下岗了，根西好几天不吃不喝躺在床上，他毕竟已跳出农门了哇，现在怎么办？想来想去想不出个好法子来，根西只好爬起来狠狠地抽烟，但烟抽了一支又一支，还是没有好法子，根西就回到了家。父子俩静静地对坐着，良久，父亲终于开口了：“娃，土地是人的根啊，不行咱回来，只要有地就饿不死！” 　　根西掐灭了手中的烟，无奈地点了点头。　　根西上地了，起初，那双稚嫩的手打出了许多血泡，他咬牙挺了过来。一年时间，他重新跟着父亲学会了种麦子，种玉米，种大豆，种各种蔬菜，根西成了种庄稼的好把式。　　第二年，根西和父亲商量，说要种地就要种出名堂来，小打小闹不行。父亲赞许地点了点头。根西就承包了村里的60亩红土坡地，他雇了两个帮手在上面栽上烟苗，一天到晚忙碌起来。秋后，除了交清承包费、付清雇工的工资外，净挣两万元。根西成了当地有名的种田大户，当上了县里的劳动模范。　　又是五月，山乡的小麦一片金黄，根西家的窑场地里，一条大汉正挥舞着镰刀在割麦，身后的空地上，码放着一排排整齐的麦铺。上午10点多，根西父亲来到地头，喊：“娃，回去吃饭。” 　　根西仍然弯着腰在那里割麦，他根本没听见父亲在叫他。父亲提高嗓门又喊了一声。　　“啊，喔，饭熟了？”根西这才醒悟过来，缓缓地站起身，用肩膀上的手巾擦了一把脸上的汗水。　　父亲上前接下镰刀，用极快的速度将两铺麦合在一起，扎了一捆就要往肩上扛。根西抢过说：“我来拿。”然后手一提将麦捆放在了肩膀上。　　五月的田埂上，走着一老一小两个庄稼汉。（选自《语文世界》2010年第6期）　　　小说结尾写道：“五月的田埂上，走着一老一小两个庄稼汉。”这一剪影式的描写给人无尽的想象，其中包含着作者怎样的情感？请你结合全文加以探究。 ____________________________________________________________________
3 已知正项数列中，，前n项和为，当时，有 .（1）求数列的通项公式；（2）记是数列的前项和，若的等比中项，求 .
4 塔里木盆地属 A.湿润地区 B.半湿润地区 C.半干旱地区 D.干旱地区
5 凡自然数是整数，4是自然数，所以4是整数，以上三段论推理 [ ] A.正确 B.推理形式不正确 C.两个“自然数”概念不一致 D.“两个整数”概念不一致
6 下列说法中正确的是 A.速度越大，惯性越大 B.一个巴掌拍不响说明力的作用是相互的 C.图钉帽较大，是为了增大压强 D.参照物的选取对描述物体运动状态无影响
7 将铁粉、铜粉、FeCl 3溶液和CuCl 2溶液，混合于某容器中充分反应（假定容器不参与反应），试判断下列情况下溶液中存在的金属离子和金属单质。 (1)若铁粉有剩余，则容器中不可能有_____________。 (2)若氯化铜有剩余，则容器中还可能有____________。 (3)若氯化铁和氯化铜都有剩余，则容器中不可能有___________，一定有__________。 (4)若氯化铁有剩余，则容器中不可能有___________。
8 Finally, I got a part – time job working at the local coffee shop. I had figured that the job would be easy. However, the actual situation was not what I had expected. The customers were hard to please. There was always too much sugar, too little ice, or not enough skimmed milk. However, I kept at it. One rainy day, Hank, one of my regular customers, came in looking sad and defeated. I asked what the problem was sand if we could help, but Hank wouldn’t tell me any details. He just said he felt like going to bed, pulling the sheets up over his head, and staying there for a few years. I knew exactly how he felt. Before he left, I handed him a bag of his favorite type of doughnuts along with his iced coffee. He looked at me skeptically because he hadn’t ordered anything else except iced coffee. “It’s on me,” I told him. “Have a nice day.” He smiled and thanked me before turning around and heading back out into the rain. The next day was a horrible one. The rain kept pouring down and I spent my afternoon hanging out the window, handing people their orders. What’s worse, no one felt like tipping that day. However, around 7:00 pm, Hank drove up to the window. Instead of ordering anything, he handed me a single pink rose and a little note. He said that few people take the time to care about others nowadays and he was glad there we still people like me in the world. I was speechless and very touched; I hadn’t thought that I had done anything incredible. The note read: Christine, Thanks for being so sweet, kind and thoughtful yesterday. I was sincerely touched by you. It is so nice to meet someone that’s nice, warm, sensitive and unselfish. Please don’t change your ways because I truly believe that you will excel. Have a great day! Hank Later, I did come across more complaining customers. But anytime I felt sad or just sick of coffee, I thought of Hank and his kindness. Then I would smile, hold my head up high, clear my throat and ask politely, “How can I help you?” 小题1:How did the author feel after he began to work at the coffee shop? A．Excited. B．Confused. C．Disappointed. D．Satisfied. 小题2:What happened to the regular customer of the author? A．He was very sick and had to stay in bed for some days. B．He was not satisfied with the coffee served to him. C．He was anxious to stay at home for a long time. D．He was not feeling himself for some reasons. 小题3:．What does the underlined word “skeptically” probably mean in the passage? A．questioningly B．hopefully C．anxiously D．excitedly 小题4:．It was Hank who helped the author realize the importance of . A．patience in one’s work B．being kind to regular customers C．taking time to care about others D．sticking to one’s own career 小题5:What is the best title of the passage? A．A Warm – hearted Man B．Coffee Shop Kindness C．My Part – time Job D．A Horrible Raining Day
9 The girl was born ________ the ________ of October, 1998. A.in…3rd B.at…3th C.on…3th D.on…3rd
10 按形态分类，细菌分为 A.球菌、杆菌、螺旋菌 B.球菌、杆菌 C.霉菌、真菌、螺旋菌 D.螺旋菌、杆菌