Respostas

2014-07-27T15:32:29-03:00
Temos: vo = 72km/h = 20m/s
v = 0
Δt = 10s

a) a = Δv / Δt
a = 20/10
a = 2m/s²

b) v = vo + at
v(t) = 20 - 2t

c)v(4) = 20 - 2.4
v = 20 - 8
v = 12m/s