Question

Problemele 3 și 4!!!

Answer 1

3. m=0.3kg

vo=10m/s

Em=?

Em=Ep+Ec

Ec=0.3*10^2/2

Ec=30/2=15J

Ep=mgh/3

Ep=0.3*10*h/3

h=?

"Folosimul ecuatia lui galilei":

V^2=vo^2+2gh

h=vo^2/2g=100:20=50m

Ep=3*h/3=50J

Em=50J+15J=65J

4.m=100kg

v1=3.6km/h=1m/s

v2=7.2km/h=2m/s

Lm=?

Em=?

DeltaV=v2-v1=1

Ec=Ep+Ec

Ec=100/2=50J

Ep=0

Em=50J

Lm=?

"Aici folosim teorema variatiei energiei mecanice":

Lm=DeltaEc

Lm=50J