Va rog frumos am nevoie in 10 minute !! Dau coroana, 30 de puncte, multumesc si 5 stele

Răspuns:
Ec = mv²/2
72km/h = 72000m/3600s = 20m/s
= 900kg×(20m/s)²/2
= 450kg×400m²/s²
= 180000 J
= 180 MJ