题目

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项Study AbroadEvery year，thousands of students choose to study abroad for the summer, six months, a year or longer. Here are some things you need to know before you make such a decision.Why do it?Living in another country will help you learn about the culture of another land. You will see the world in a new way. Many companies today want employees who speak a second language or who have experienced living or working in another country.Making the right choice. To choose the r（12分）如图所示为某工厂将生产工件装车的流水线原理示意图。设AB段是距水平传送带装置高为H=1.25m的光滑曲面，水平段BC使用水平传送带装置传送工件，工件经C点抛出后落在固定车厢中。已知BC长L=3m，工件可视为质点，传送带与工件间的动摩擦因数为μ=0.4。设质量m=lkg的工件由静止开始从A点下滑，经过B点的拐角处无机械能损失，取g= l0m/s2。求： （1）当传送带静止时，工件运动到C点时的速度是多大？ （2）当传送带以v=8m/s顺时针方向匀速转动时，在工件运动到C点的过程中因摩擦而产生的内能是多少？