您所在的当前位置：高中物理试题 >

共点力的平衡

> 如图所示，一个质量为m的滑块静止置于倾角为30°的粗糙斜面上，一根轻弹簧一端固定在竖直墙上的P点，另一端系在滑块上，弹簧与竖直方向的夹角为30°。则（　　） A．滑块一定受到四个力作用 B．弹簧一定处于压缩状态 C．斜面对滑块一定有支持力 D．斜面对滑块的摩擦力大小可能等于零

问题：

发布时间：2024-09-13

如图所示，一个质量为m的滑块静止置于倾角为30°的粗糙斜面上，一根轻弹簧一端固定在竖直墙上的P点，另一端系在滑块上，弹簧与竖直方向的夹角为30°。则（　　）

A．滑块一定受到四个力作用 B．弹簧一定处于压缩状态

C．斜面对滑块一定有支持力 D．斜面对滑块的摩擦力大小可能等于零

参考答案：

提问用户：uM***CcO

可能感兴趣的题目：

1 如图所示，已知A ，B ，C 三点不共线，P 为一定点，O 为平面ABC 外任意一点，则下列能表示向量的为 [ ]
2 阅读理解。 Su Hua is studying at Cambridge, UK. She has bought a bicycle and is worried about security (安全). Her friend, Kate, found this article and sent it to her. Introduction A lot of crime is against bicycles. About 150,000 bicycles are stolen every year and most are never found. You can prevent this happening by following a few careful steps. Basic Security Do not leave your bicycle in out-of-the-way places. Always lock your bicycle when you leave. Secure it to lampposts or trees. Take off smaller parts and take them with you, for example lights and saddles (车座). Locks Get a good lock. There are many different types in the shops. Buy one that has been tested against attack. Ask for a recommendation from a bike shop. Marking Security marking your bike can act a deterrent to a thief. It can also help the police find your bicycle. It should be clearly written and include your postcode and your house or flat number. This will provide a simple way to identify your bicycle. Registration There are a number of companies who will security mark your bicycle for you. They will then put your registration number and personal details on their computer database. Then if your bicycle is found it will be easy to contact you. Finally Keep a record of the bicycle yourself: its make, model and registration number. You can even take a photograph of it. This will prove the bicycle belongs to you. 1. Which part of the text gives you information on how to lock up your bicycle when you leave it? A. Locks. B. Marking. C. Registration. D. Basic Security. 2. The underlined phrase "act as a deterrent to a thief" means _____. A. help you recognize your bike B. help the police find your bicycle C. stop someone stealing your bicycle D. stop you worrying about your bike 3. The article advises you to keep a record of your bicycle ______. A. in the bike shop and your computer B. in the police station and a security company C. in a security company and your university D. by yourself and in a security company 4. The main purpose of this article is _____. A. to tell you what to do if your bicycle is stolen B. to suggest ways of keeping your bicycle safe C. to give you advice on where to buy a good lock D. to say why you shouldn"t keep your bicycle in a quiet place
3 软性隐形眼镜可由聚甲基丙烯酸羟乙酯(HEMA) 制成超薄镜片，其合成路线可以是：已知：试写出：（1）A、E的结构简式分别为：A、，E、。（2）写出下列反应的反应类型：A→B ，E→F 。（3）写出下列转化的化学方程式： I→G ； C→D 。
4 邓小平，这个令国人敬仰、让世界瞩目的名字，作为一个时代的象征、一个国家和民族的旗帜，他永远与我们在一起。下列选项中的会议和邓小平理论形成有密切关系的是（） A．一届人大中共十一届三中全会 B．中共八大中共十二大 C．中共十一届三中全会中共十五大 D．中共十五大中共十七大
5 如图所示，在磁场中悬挂一根导体ab，闭合开关，不能使电路里产生电流的做法是（　　） A．导体ab不动，磁体向右运动 B．磁体不动，导体ab向右运动 C．磁体不动，导体ab竖直向上运动 D．磁体不动，导体ab斜向上运动
6 2005福建，33） When_______help, one often says “Thank you.” or “It’s kind of you”. A．offering B．to offer C．to be offered D．offered
7 The big strike of the workers would _______ the production of cars for several months. [ ] A. hold down B. hold on C. hold with D. hold up
8 依次填入下列句子横线处的词语，最恰当的一项是（3分） ①由于人类文明史和意识形态史对文章的_______，人们对文章总是有着习惯性的推崇。 ②这家企业改革的主要任务，_______是裁减职员，更重要的是增加工作效益。 ③梅派艺术博大精深，在京剧艺术发展过程中，它的作用是_______的。 A．器重不止不同凡响 B．器重不只不同凡响 C．倚重不止不可估量 D．倚重不只不可估量
9 下列各句标点符号使用正确的一项是( ) A．但这回却很有几点出于我的意外。一是当局者竟会这样地凶残；一是流言家竟至如此之下劣；一是中国的女性临难竟能如是之从容。 B．她认真地看过这些信后，郑重地转给了有关部门，不知道有关部门收到这些信后作何感想? 能不能像影片中那位女法官那样秉公断案，尽快解决问题? C．每当疼痛发作，他就采用自己的“压迫止痛法”—用茶壶盖、烟嘴、玻璃球、牙刷把等顶住疼痛的部位。 D．“二拍”与“三言”不同，基本上都是个人创作，“取古往今来杂碎事可新听睹、佐谈谐者，演而畅之。”（二刻拍案惊奇小引）
10 默写（6分）小题1:外无期功强近之亲，______________________，_____________，________________。小题2:何以解忧？唯有杜康。___________________，____________________。小题3:____________________，依依墟里烟。小题4:报养刘之日短也。____________，____________。臣之辛苦，非独蜀之人士及二州牧伯所见明知……________________，死当结草。小题5:__________________，池鱼思故渊。小题6:__________________________，不尽长江滚滚来。小题7:____________，谈笑间，樯橹灰飞烟灭。