Respostas

2014-03-30T15:51:03-03:00
A) x = -20 + 5t
   x = -20 + 5.10
   x = -20 + 50
   x = 30m

b) x = -20 + 5t
   0 = -20 + 5t
   5t = 0 + 20
   5t = 20
   t = 4s
1 5 1