Question

De la inaltimea h=200 cade liber un corp cu m=5 kg, cu ce viteza ajunge la pamant? Ce energie are la jumate distanta?

Answer 1

v²=vo²+2gh=0²+2*10*200=20*200=4000 =>v=√4000=63,24 m/s
d=h/2=200/2=100 m
Ep=mgd=5*10*100=5000 J
v1²=vo²+2gd=2*10*100=2000=>v1=√2000=44,72 m/s
Ec=mv1²/2=5*2000/2=5000 J
E=Ec+Ep=5000+5000=10000 J