Aplicam legea miscarii uniforme(rectilinie)
Δd=v·Δt sau Δt=Δd/v
Δt=2h ⇔Δd/v=2h
Presupunem v2 astfel incat
v2=75/100 ·v=3/4 ·v=3v/4
Asadar obtinem
Δd/3v/4=4·Δd/3v=4/3 ·Δd/v=4/3 ·2h=2,(6)h.
Presupunem t2 astfel incat
t2=2,(6)h-2h
t2=0,(6)h=6/9 h=2/3 h⇒va ajunge mai tarziu cu 2/3 h.