Respostas

2014-03-25T16:29:57-03:00
Calculando a aceleração

V = Vo + at
50 = 0 + a*20
50/20 = a

a = 5/2

a = 2,5m/s²
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Fr = m * a
Fr = 3 * 2,5

Fr = 7,5N
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