1. The problem statement, all variables and given/known data Two particles are at the same point at the same time, moving in the same direction. Particle A has an initial velocity of 6.9 m/s and an acceleration of 1.8 m/s2. Particle B has an initial velocity of 2.4 m/s and an acceleration of 5.7 m/s2. At what time will B pass A? 2. Relevant equations [itex]\Delta[/itex]x = vit + 1/2at2 3. The attempt at a solution I'm just wondering what equation I should use for this. I think I need to set up a system, but I don't see why I would need displacement for this. The only information the question gives us is vi for both, the acceleration for both, and the fact that they're going the same direction. I really don't understand how I would go about solving it. Knowing the equation(s) to use would be a great start! I'm really discouraged. I just tried setting two equations equal and I got the wrong answer... I don't know what to do. Thank you so much! EDIT: I calculated with the quadratic equation wrong somehow, but found the answer.