Question

apa curge cu v de 2m/s. ce energie cinetica poseda 1m cub de apa ? 

Answer 1

Pentru apă, $1l=1kg$ ⇒ $1m^3=1000dm^3=1000l=1000kg$
⇒ $E_c= \frac{mv^2}{2}= \frac{1000kg*4 (\frac{m}{s})^2 }{2}=2000J=2kJ$

Answer 2

Ec=mv²/2
m=V·p=1m³·1000kg/m³=1000kg
Ec=1000*4/2=2000J