平均速度分别是5m/s和10m/s设其初速度为 x,加速度为y~则可得:x+(x+20y)=2*5(x+20y)+(x+20y+10y)=2*10解上面方程得:x=5/3m/s,y=1/3m/s。
解:v1=s1/t1=100/20m/s=5m/sv2=s2/t2=100/10m/s=10m/sv平均=(s1 s2)/(t1 t2)=200/15m/s=13.3m/s由s=1/2*at^2得a=2s/t^2=1.77m/s^2