皮皮学，免费搜题
登录
搜题
【简答题】
如图所示，在竖直平面内有一半径为R的3/4圆弧轨道，半径OA水平、OB竖直，一个质量为m的小球自A的正上方P点由静止开始自由下落，不计空气阻力，小球沿轨道到达最高点8时恰好对轨道没有压力。已知PA=2．5R．重力加速度为9。关于小球从P到曰的运动过程，说法错误的是（ ）。
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【简答题】New York, London, Paris and other big cities are exciting places to live in. There are many interesting things to see and to do. You can go to different kinds of museums, parks and cinemas. You can al...
【单选题】In fact, most people in some developed countries are ___ than they were two years ago because of the global financial crisis.
A.
poorer off
B.
badly off
C.
worse off
D.
richer off
【简答题】In some rural places, police use ( ) (无人机) to monitor people in groups. In some places, people also use them to ( ) (消毒) their communities.
【简答题】A．People in some developing countries have realized that the world's resources are limited. B．People in developed countries do not care much about common properly. C．Laws have to be passed to protect ...
相关题目：
参考解析：
知识点：
题目纠错 0
发布
