m=500g=0,5kg
vO=20m/s
9=10n/kg
a)g=m*g=0,5kg*10n/kg=5n
b)h=1m
ec=n*vo (pui un 2 deasupra lui vo)=0,5x(20n/s)=100j
ep-n*g*h=0,5kg*10n/kg*1n
c)v(pui iar 2 deasupra =) )=vo (doi seasupra again)+2*g*h
=29h=(20n/s)-0=400(n/s)
h=400n/20=20n
d)l=g*h=5n*20n=100j