长为l的均质杆,质量为m,绕一侧端点以角速度转动,则杆件的动能为( )。

A、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/153967404111232f5fc85b24544db80de1fa797d12bc2.png" alt="上传图片"><br>

B、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1539674048248813ba8e02c1d4d32b08e9a5ede55fc61.png" alt="上传图片"><br>

C、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1539674055489ce3faa11d4574fec8b90b3320e11ad06.png" alt="上传图片"><br>

D、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1539674063413e00cabe81e3a4b41afd6f39aa3ee0876.png" alt="上传图片"><br>