Ubuntu中文支持
1 | sudo apt-get install language-pack-zh-hant language-pack-zh-hans |
添加:
1 | LANG="zh_CN.UTF-8" |
1 | sudo dpkg-reconfigure locales |
1 | sudo apt-get install language-pack-zh-hant language-pack-zh-hans |
添加:
1 | LANG="zh_CN.UTF-8" |
1 | sudo dpkg-reconfigure locales |
Sublime安装JavaScript&NodeJS Snippets
插件1。
Tools - Build System - New Build System
,输入23:
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20{
"cmd": ["/Users/luohanjie/.nvm/versions/node/v4.2.6/bin/node", "$file"],
"file_regex": "^[ ]*File \"(...*?)\", line ([0-9]*)",
"selector": "source.js",
"shell":true,
"encoding": "utf-8",
"windows":
{
"cmd": ["taskkill /F /IM node.exe", ""],
"cmd": ["node", "$file"]
},
"linux":
{
"cmd": ["killall node; node", "$file"]
},
"osx":
{
"cmd": ["killall node; /Users/luohanjie/.nvm/versions/node/v4.2.6/bin/node $file"]
}
}
注意node
的绝对地址。然后保存为Nodejs.sublime-build
并且选择Tools - Build System - Nodejs
建立一个新js文件,输入console.log("ok");
,
按Control + B
,应该会输出:
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3No matching processes belonging to you were found
ok
[Finished in 0.1s]
我们假设质点进行匀速圆周运动,有:\[\left| {\vec {v_1} } \right| = \left| {\vec {v_2} } \right|\]
因为两个绿色区域相似,有:\[\frac{\left| {\vec {\Delta r} } \right|}{\left| {\vec r} \right|} = \frac{\left| {\vec {\Delta v} } \right|}{\left| {\vec v} \right|}\] 因为路程=速度*时间,当\(\theta \to 0\)时,有:\[\left| \vec {\Delta r} \right| = \left| {\vec v} \right|\Delta t\]
\[\frac{\left| \overrightarrow {\Delta r} \right|}{\left| \overrightarrow r \right|} = \frac{\left| {\vec v} \right|\Delta t}{\left| {\vec r} \right|} = \frac{\left| {\overrightarrow {\Delta v} } \right|}{\left| {\vec v} \right|}\]
\[\therefore \frac{ {\vec v}^2 \Delta t }{\left| \vec r\right|} = \frac{\left| \vec {\Delta v} \right|}{\Delta t} = \vec a \]
当\(t \to 0\)时成立。最后有:
\[\vec a = \frac{ {\vec v}^2}{\left| {\vec r} \right|}\overrightarrow n\]
\(\overrightarrow n\)为法向量,指向圆心;\(\vec a\)即为向心加速度。