Respostas

2014-04-01T21:48:12-03:00
D = m/V
m = d*V

7,9*50000 =  395000 /1000 (pra tranformar em kg) = 395 kg.
2014-04-01T21:51:44-03:00
7,9 Grama [g]   =   0,0079 Quilograma [kg]

m=d*v
m= 0,0079*50.000
m= 395 kg