题型:判断题 如图所示,一质量m1=0.45kg的平板小车静止在光滑的水平轨道上.车上右端放一质量m2=0.2kg的小物体,小物体可视为质点.现有一质量m0=0.05kg的子弹以水平速度v0=100m/s射中小车左端,并留在车中,最终小物块以5m/s的速度与小车脱离.子弹与车相互作用时间很短,g取10m/s2.求:①子弹刚刚射入小车时,小车的速度大小.②小物块脱离小车时,小车的速度多大. 查看答案
题型:判断题 He did not regret saying what he did but felt that he ______ it differently. [ ]A. could express B. would express C. could have expressed D. must have expressed 查看答案