(1)
S=S1+S2
=Vo*0.4+Vo^2/2a
=15*0.4+225/2*5
=6+22.5
=28.5m
(2)
刹车总时间t=0.4+Vo/a=0.4+15/5=3.4s
自行车在这段时间行进
X=V自*t=5*3.4=17m
X