1. The problem statement, all variables and given/known data In this problem, the solution says that aB= -(aA/6). But from what I know, acceleration is positive whenever an object is speeding up in the positive direction or when an object is slowing down in the negative direction. According to the problem, car B is slowing down and towards the negative direction with the assumption that going to the right is the positive direction. So why is aB= -(aA/6)? Should'nt it be aB= +(aA/6) since it is slowing down in the negative direction? 2. Relevant equations N/A 3. The attempt at a solution Maybe the sign depends on only deceleration or acceleration and not on direction in this problem? If this is the case, I'm still confused as to why the direction isn't a factor.