Răspuns:
1. 1000J
2. 9000J sau 9KJ
Explicație:
1. F=G
G=m·g
G=[tex]50kg[/tex]·[tex]10\frac{N}{Kg}[/tex]
G=500N
L=F·d= 500N·2m=1000J
2.
72 km/h=20m/s
[tex]E_{c} =\frac{900 kg * 20\frac{m}{s}^{2} }{2} = 9000\frac{kg*m}{s^{2} } * 1m =9000N*m= 9000J = 9KJ[/tex]