题目

写作部分;阅读下面的材料，然后根据材料内容回答所提问题 I’m Simon from America．I am twelve and I’m at Wllize．junior School(初中)．This month We have two school events(事件)．One is an English party and one is a school trip．Next month，there will be five events． here is a list．  DateEvent May12School Day May15-17English speech Contest  3:00pm--4:30pm May18Volleyball game 2:00--3:30pm May19Art Festiva 19:00am--5:00pm May24Music party 6:00--9:00pm    I'm in the school volleyball club．1 also like singing．1 want to play in the volleyb18．如图所示，水平传输带以v=20m/s的速度匀速向右运动，左右两边端点A、B的间距为L=10m．传输带左边接倾斜直轨道AC，AC轨道与水平面夹角为θ=37°．传输带右边接半圆形轨道BD并相切于B点，BD轨道半径R=2m．两轨道与传输带连接处认为紧密圆滑，物体通过连接点时无机械能损失．有一可视为质点的物体从B点出发以初速度v0向左运动．已知物体与传输带的动摩擦因数为μ1=0.4，物体与斜面的动摩擦因数为μ2=0.3，圆轨道光滑．问：v0至少多大，物体才能运动经过D点？（AC斜面足够长，结果保留3位有效数字）