2022英语周报外研第48期答案

26.解:(1)碰撞后a沿轨道运动,设a恰好通过最高点C时的速率为v,有nR(2分)根据机械能守恒定律有2m2=2m2十mkx2R(2分)解得v=3m/s。(1分)(2》与a发生弹性碰撞,设碰撞前、后瞬间b的速率分别为v、,有mv=m防一mw(2分)m=号m2 号m(1分)解得v=6m/s,w=3m/s(1分)由能量守恒定律有2他=pmg×2L(1分)解得L=1m(1分)从用手开始将b向石压缩弹簧到b第一次到达A处的过程中,根据动能定理有W-pm;k=2mv(2分)解得W=2.025J。(1分)(3)设b停在车上时b与车的共同速度大小为v,b在小车上表面P点左侧运动的相对路程为x,由动量守恒定律有m边=(M m)w(2分)由能量守恒定律有2m2=2(M m)动2 pmkx(2分)解得x=1.6m(1分)b最终停在P点左侧x-L=0.6m处。(1分)

第三节One possible version:Paragraph 1After reading the diary, the son was filled with tearsand began to reflect on the days when he used to sitogether with his father. His father would patiently answerthe same question all 23 times without feeling irritationwhile his father asked him the same question just fourtimes! The son thought to himself: If I attain old age, howwill my son look at me? Will he think of me as a burden?Will he shout at me because of my poor sight, poor hearingor poor understanding?

以上就是2022英语周报外研第48期答案，更多英语周报答案请关注本网站。