Respostas

2014-06-01T17:00:13-03:00
Δv= Velocidade Δt= Tempo 
At=Δv/Δt
At=420/15
At=28m/s²
2014-06-01T17:00:31-03:00
V=v0+at
420=a15
a=420/15=28m/s2