搜题请搜索小程序“爱下问搜题”
问题 单项选择题

极坐标法放样点位，适用于______，并且放样点位离控制点较近，又便于测量距离。其计算和操作都比较简单灵活。

A．平坦地带
B．丘陵地区
C．多山地区
D．高原地带

答案

参考答案：A

听力题

Hello. My name is Chen Lei. I study in Sunson Middle School-- a小题1:(美丽) school with more than 5000 students and小题2:(教师). My home is only two【小题3】(公里).So I walk there every day. It小题3:(通常) takes me about 20 minutes. I often小题4:(看) books and newspapers in the小题5:(图书馆) because it’s小题6:(安静) and I can get there小题7:(容易地).

I have a pen pal from小题8:(加拿大). There are four小题9:(儿童) in his family. His parents are小题10:(严格) with them. He 【小题12】(锻炼) every day. So he is healthy and never goes to小题11:(医院). He enjoys小题12:(爬) mountains and the  【小题15】(故事) telling is his favorite. Do you like him?

查看答案
计算题

如图甲所示，质量为m的物体沿倾角为θ的固定粗糙斜面由静止开始向下运动，风对物体的作用力沿水平方向向右，其大小与风速v成正比，比例系数用k表示，物体加速度a与风速v的关系如图乙所示，求：

（1）物体与斜面间的动摩擦因数μ；

（2）比例系数k。

查看答案