您所在的当前位置：初中物理试题 >

电学

> 将带负电的物体靠近挂在细线下的轻质球，小球被吸引，这时若换用带正电的物体去靠近小球，则小球 A.静止不动 B.一定被排斥 C.一定被吸引 D.可能被吸引，也可能被排斥

问题：

发布时间：2024-09-13

将带负电的物体靠近挂在细线下的轻质球，小球被吸引，这时若换用带正电的物体去靠近小球，则小球

A.静止不动
B.一定被排斥
C.一定被吸引
D.可能被吸引，也可能被排斥

参考答案：

提问用户：fj***Dnd

可能感兴趣的题目：

1 已知 m =(sinωx+cosωx， 3 cosωx)， n =(cosωx-sinωx，2sinωx)，其中ω＞0，若函数 f(x)= m • n ，且函数f（x）的图象与直线y=2相邻两公共点间的距离为π．（Ⅰ）求ω的值；（Ⅱ）在△ABC中，a、b、c分别是角A、B、C、的对边，且 a= 3 ，b+c=3，f（A）=1，求△ABC的面积．
2 氯水用于消毒是因为 A．氯水中含有氯分子 B．氯水中含有次氯酸分子 C．氯水中含有氯离子 D．氯水中含有氢离子
3 下列各组离子在碱性条件下可以大量共存，而在强酸性条件下能发生氧化还原反应的是 [ ] A．Cu2+、Fe2+、NO3-、Cl- B．K+、Mg2+、HCO3-、SO42- C．Na+、K+、S2-、SO42- D．Ba2+、Na+、I-、Cl-
4 汽车以2 m／s 2的加速度由静止开始起动，则第5 s末汽车的速度是_________m/s，5s内汽车的平均速度是____________m／s，第5 s内汽车的位移是___________m。
5 阅读理解。 People do not analyze every problem they meet. Sometimes they try to remember a solution from the last time they had a similar problem. They often accept the opinions or ideas of other people. Other times they begin to act without thinking. They try to find a solution by trial and error. However, when all these methods fail, the person with a problem has to start analyzing. There are six stages in analyzing a problem. First the person must recognize that there is a problem. For example, Sam"s bicycle is broken, and he cannot ride it to class as he usually does. Sam must see that there is a problem with his bicycle. Next the thinker must define the problem. Before Sam can repair his bicycle, he must find out the reason why it does not work. For instance, he must determine if the problem is with the gears, the brakes, or the frame. He must make his problem more specific. Now the person must look for information that will make the problem clearer and lead to possible solutions. For instance, suppose Sam decided that his bike does not work because there is something wrong with the gear wheels. At this time, he can look in his bicycle repair book and read about gears. He can talk to his friends at the bike shop. He can look at his gears carefully. After studying the problem, the person should have several suggestions for a possible solution. Take Sam as an illustration. His suggestions might be: put oil on the gear wheels; buy new gear wheels and replace the old ones; tighten or loosen the gear wheels. Eventually one suggestion seems to be the solution to the problem. Sometimes the final idea comes very suddenly because the thinker suddenly sees something new or sees something in a new way. Sam, for example, suddenly sees that there is a piece of chewing gum between the gear wheels. He immediately realizes the solution to his problem: he must clean the gear wheels. Finally the solution is tested. Sam cleans the gear wheels and finds that afterwards his bicycle works perfectly. In short, he has solved the problem. 1. By referring to Sam"s broken bicycle, the author intends to ______. A. illustrate the ways to repair his bicycle B. discuss the problems of his bicycle C. tell us how to solve a problem D. show us how to analyze a problem 2. Which of the following is NOT true? A. People do not analyze the problem they meet. B. People often accept the opinions or ideas of other people. C. People may learn from their past experience. D. People can not solve some problems they meet. 3. As used in the last sentence, the phrase "in short" means ________. A. in the short term B. in detail C. in a word D. in the end 4. In analyzing a problem we should do all the following except . A. recognize and define the problem B. look for information to make the problem clearer C. have suggestions for a possible solution D. find a solution by trial or mistake
6 The teachers are supposed to teach us about “safe sex” but most of them are too________. A．embarrassed B．allergic C．funny D．worried
7 下列说法正确的是（） A．平原区只能发展种植业，山区只能发展畜牧业 B．我国将橡胶生产由热带向北推广到北纬22°，这是改造自然的结果 C．市场的需求量最终决定了农业生产的类型和规模 D．自然因素是影响农业区位的决定性因素
8 一倾角为θ=45°的斜面固定于地面，斜面顶端离地面的高度h 0=1m，斜面底端有一垂直于斜面的固定挡板，在斜面顶端自由释放一质量m=0.09 kg的小物块（视为质点）。小物块与斜面之间的动摩擦因数μ=0.2，当小物块与挡板碰撞后，将以原速返回。重力加速度g=10 m/s 2。在小物块与挡板的前4次碰撞过程中，挡板给予小物块的总冲量是多少？
9 There is a big desk between ______ and ______. A.he; I B.he; me C.him; I D.him; me
10 A．as a result B．as the result C．as a result of which D．as a result of