周期 T=2s ,ω=2π/T=π/s , A=2m , x=Acos(ωt-π/2)=2cos(πt-π/2)v=-2π.sin(πt-π/2)a=-2π^2.cos(πt-π/2)=-(π^2)x a1=-(π^2)*2= -2π^2m/s , a2=-(π^2)0=0a3=-(π^2)(-2)= 2π^2m/s , a4=-(π^2)0= 0a5=-(π^2)2=-2π^2m/s , a6=-(π^2)0=0