把t消掉：t=（v-v0）/a带入2式：x=v0t+0.5at^2=v0(v-v0)/a+0.5a(v-v0)^2/a^2=(v0v-v0^2)/a+(0.5v^2+0.5v0^2-vv0)/a两边同乘2a:2ax=2vv0-2v0^2+v^2+v0^2-2vv0=-2v0^2+v^2+v0^2=v^2-v0^2