题目

某校兴趣小组制作了一个游戏装置，其简化模型如图11所示，在A点用一弹射装置可将静止的小滑块以水平速度弹射出去，沿水平直线轨道运动到B点后，进入半径R=0.3m的光滑竖直圆形轨道，运行一周后自B点向C点运动，C点右侧有一陷阱，C、D两点的竖直高度差h=0.2m，水平距离s=0.6m，水平轨道AB长为L1=1m，BC长为L2 =2.6m，小滑块与水平轨道间的动摩擦因数μ=0.5，重力加速度g=10m/s2。 （1）若小滑块恰能通过圆形轨道的最高点，求小滑块在A点弹射出的速度大小 词汇运用   difficulty         carry          like          nervous        since     1.Are you ____________ about your grades ? 2.Never give up when you meet ___________ in your life 3.The bag is too heavy for the little girl to _________. 4._______they live in one house with their parents, they should know everyone should do their part in keeping it clean and tidy . 5.This group was set up to help disabled people ________Ben Smith .