最好解释一下,感谢
不好意思啊,是π/2
x=Acos(wt+π/2),v=w*Asin(wt+π/2),Ek=m(wA)^2*sin^2(wt+π/2)/2,t=0,Ek=m(wA)^2*sin^2(w*0+π/2)/2=m(wA)^2/2,t=T/8,w*T/8=π/4,Ek=m(wA)^2*sin^2(π/4+π/2)/2=m(wA)^2/4,动能之比:1/2比1/4,或,2比1