Respostas

2014-07-21T11:47:09-03:00
A)  
F = m.a
F1 + F2 = 4 . a
10 + 6 = 4a
a = 16/4 = 4m/s²

B)
F = m.a
F1 - F2 = m . a
10 - 6 = 4 . a
4a = 4
a = 4/4 = 1m/s²