您所在的当前位置：初中物理试题 >

物质的物理特征

> 一物体做变速直线运动，在前2s内通过的路程是8m，在后3s内通过的路程是27m．则该物体 A.在前2s内运动的平均速度是4m/s B.在后3s内运动的平均速度是9m/s C.在整个5s时间内的平均速度是6.5m/s D.在整个35m路程上的平均速度是7m/s

问题：

发布时间：2024-09-09

一物体做变速直线运动，在前2s内通过的路程是8m，在后3s内通过的路程是27m．则该物体

A.在前2s内运动的平均速度是4m/s
B.在后3s内运动的平均速度是9m/s
C.在整个5s时间内的平均速度是6.5m/s
D.在整个35m路程上的平均速度是7m/s

参考答案：

提问用户：f0***xpH

可能感兴趣的题目：

1 在中，角A，B，C对应边分别是a，b，c，，，，则等于( ) A． B． C． D．
2 下图是运用某种地理信息技术来选址的工作流程图。读图回答小题。小题1:最有可能采用图示流程进行选址的设施是 A．地下水天然入渗补给区 B．汽车加油站 C．大型游乐园 D．放射性废弃物储存场小题2:图中甲和乙所进行的分析方法是 A．最佳路线分析 B．风险分析 C．生态分析 D．叠加分析
3 如右图所示，在光滑水平面上质量分别为m A=2kg、m B=4kg，速率分别为v A=5m/s、v B=2m/s的A、B两小球沿同一直线相向运动( ) A．它们碰撞前的总动量是18kg·m/s，方向水平向右 B．它们碰撞后的总动量是18kg·m/s，方向水平向左 C．它们碰撞前的总动量是2kg·m/s，方向水平向右 D．它们碰撞后的总动量是2kg·m/s，方向水平向左
4 （12分）空军特级飞行员李峰驾驶歼十战机执行战术机动任务，在距机场54公里、离地1170米高度时飞机发动机停车失去动力。在地面指挥员的果断引领下，李峰使飞机安全迫降机场，成为成功处置国产单发新型战机空中发动机停止故障、安全返航第一人。若飞机着陆后以6 的加速度做匀减速直线运动，且着陆速度为60 ，求：（1）着陆后12 内飞机滑行的距离；（2）静止前4 内飞机滑行的距离。
5 一个伪代码如右图所示，输出的结果是______．
6 你认为下列选项中，不属于上海发展钢铁工业的有利条件 A.铁矿资源丰富 B.交通便利 C.市场广阔 D.技术力量雄厚
7 某学生用自来水配制下列物质的溶液，不会产生明显药品变质的是（） A．石蕊 B．硝酸银 C．氢氧化钠 D．氯化铝
8 阅读理解。 Dr. Glenn Tisman, a cancer specialist, knew his young neighbor, Ray Bateman, had an unusual mind. But he had no idea at the time that 12-year-old Ray had the ability to become his partner in cancer research. Ray" s parents remembered that at age four, Ray surprised them by fixing a broken vacuum cleaner (吸尘器). When he was ten, he speedily constructed the family color television from a kit.Later, he succeeded in assembling (组装) a complex stereo system after two experts had failed to do the job. When Ray was ten, he convinced his parents to buy him a computer.In a short time, Ray was able to do amazing things with the computer.Ray shared his enthusiasm for computers with Dr. Tisman, who used a computer for his research. The two discussed computers and medicine frequently.Amazingly, Ray understood the biology and chemistry related to Dr. Tisman"s medical research without any previous instruction. Ray then worked with Dr. Tisman after school.He helped conduct research with the equipment and kept it in working order.The purpose of the research was to test the effectiveness of mixing an old cancer drug with certain vitamins.Ray analyzed patient test results by computer, while Dr. Tisman handled all patient contact.Together, they came up with solid research that helped advance cancer treatment. In 1988, 14-year-old Ray went with Dr. Tisman to a meeting of the American Federation for Clinical Research (AFCR) , where Ray presented their initial research findings.Using terminology (术语) beyond the grasp of most kids of his age, Ray told the scientists how the new drug mixture caused fewer and milder side effects for cancer patients. A year later, Ray returned to the meeting to update the findings of his and Dr. Tisman" s research. By then, he had become well-known for his devotion to finding cures for sick patients.Stories about him appeared in hundreds of newspapers around the world.He appeared on television newscasts and talk shows. Ray continued to spend most free hours working with Dr. Tisman.The two began studying the effects of vitamins on babies inside the womb.However, Ray" s main interest remained cancer treatment, and he continues his research today. 1. According to the passage, Ray______. A. is a boy of many gifts B. is very helpful to his parents C. learned fast under Dr. Tisman" s instruction D. stopped working with Dr. Tisman after his success 2. What do we know about Dr. Tisman? A. He succeeded in finding cures for cancer. B. He made a new discovery in cancer treatment. C. He convinced Ray to become a partner of him. D. He taught Ray knowledge related to his research. 3. What made Ray first known to the medical world? A. His presentation at AFCR. B. His great skills in computer. C. His devotion to cancer research. D. His appearance on television newscasts. 4. Dr. Tisman"s research is aimed at ______. A. providing different cancer treatments B. proving the effects of vitamins on babies C. finding the side effects of a cancer drug D. testing the effectiveness of a new drug mixture
9 把多项式xy 2-16x分解因式，结果正确的是 A.x（y2-16） B.x（y-4）2 C.x（y+4）（y-4） D.x（y+8）（y-8）
10 某物体作直线运动，前三分之一的路程速度为v 1，后三分之二的路程速度为v 2，则该物体全程的平均速度为 A.（v1+v2）/2 B.（v1+2v2）/3 C.（3v1v2）/（2v1+v2） D.（3v1v2）/（v1+2v2）