Răspuns:
Explicație:
vm=d/t
d₁=v₁.t₁
d₁=d/3
d/3=v₁.t₁
t₁=(d/3)/v₁=d/3v₁
d₂=v₂.t₂
d₂=2d/3
2d/3=v₂.t₂
t₂=(2d/3)/v₂=2d/3v₂
t=t₁+t₂=d/3v₁+2d/3v₂=d/3(1/v₁+2/v₂)
vm=d/{d/3(1/v₁+2/v₂)} se simplifica d
v₁=14,4km/h=14,4.1000m/3600s=4m/s
vm=3/(1/4+2/6)=5,14m/s
