Respostas

2014-08-08T17:01:04-03:00
A = VM / TEMPO 

VM FINAL - VM INICIAL / TEMPO = ACELERAÇAO 

LOGO 120 - 20 / 2 = A 

100 / 2 = A 
50 KM/H = Aceleraçao
2014-08-08T17:02:37-03:00
a = Vf - Vo/t
a = 120-20/2
a = 100/2
a = 50 km/h