d1=v1×t1
d2=v2×t2
d=d1+d2=v1×t1+v2×t2
Dar d=vm×(t1+t2)
Egalind obtinem
v1×t1+v2×t2=vm×(t1+t2)
Calculam t2:
(v1-vm)×t1=(vm-v2)×t2
Raspuns:
t2=t1×(v1-vm)/(vm-v2)
d=vm×(t1+t2)
Numeric:
v1=54km/h
t1=30min=1/2h
v2=90km/h
vm=60km/h
Calculele numerice le faci tu. Succes!