Question

O masina parcurge o distanta in 4 ore, mergand cu o viteza medie de 100km/h. In cat timp va parcurge masina aceiasi distanta daca ar merge cu 120 km/h ?
P. S . E regula de trei simpla .

Answer 1

d=vxt
d=100x4=400

t=d/v=400/120=3.3

la regula de trei simpal este asa


4 ore....100km/h
 x ore......120km/h

x=120x4:100=4,8h

Answer 2

Δd=Δt·v
⇒Δd=4ore·100km/h
⇒Δd=4·100km
⇒Δd=400km;
⇒daca v=120km/h
          Δd=400km
⇒Δt=Δd/v
⇒Δt=400km/120km/h
⇒Δt=400/120[h]
⇒Δt=3,[3]h;