Respostas

2014-03-06T21:12:29-03:00
a -  Vo = 0
b - H = 5t²
80 = 5t²
t² = 16
t = 4 s
c -  V = Vo + at
V = 0 + 10t
V = 10t
V = 10*4
V = 40 m/s