o macara ridica uniform la inaltimea de 14 m un corp cu masa de 350 kg in 20 secunde g=10 N/kg
calculeaza lucru meanic motor si putera mecanica a motorului macaralei
h=14 m m=350 kg t=20 s g=10 N/kg L=? P=? L=F·d F=G G=m·g G=350 kg·10 N/kg G=3500 N F=3500 N d=h d=14 m L=3500 N·14 N L=49000 J P=L/t P=49000 J/20 s P=2450 W.
