v₁=3v₂/5
v₁+v₂=3v₂/5+v₂=8v₂/5
τ=(3*2+1)/2=7/2=3,5 h
x₁=v₁t
x₂=d-v₂t
x₁=x₂=>v₁t=d-v₂t<=>t(v₁+v₂)=d=>t=d/(v₁+v₂)=d/8v₂/5=320/8v₂/5=200/v₂
x₂=d-v₂t=320-v₂*200/v₂=320-200=120 km
x₁=d-x₂=320-120=200 km
Δx₁=v₁τ
Δx₂=D-v₂τ
Δx₁=Δx₂=v₁τ=D-v₂τ<=>τ(v₁+v₂)=D=>v₁+v₂=D/τ=40/3,5=11,42
8v₂/5=11,42<=>8v₂=57,1=>v₂=7,13 km/h
v₁=3v₂/5=3*7,13/5=4,28 km/h
v₁=4,28 km/h
v₂=7,13 km/h
T=d/v₂=320/7,13=44,88 h
T=44,88 h