Respostas

2014-02-10T21:19:26-02:00
V² = Vo² + 2*a*/\S
0 = 6² + 2*a*8
-36 = 16a

a = -36/16 = -9/4 = - 2,25m/s²

Fr = m * a
Fr = 3 * 2,25
Fr = 6,75N. 
1 5 1