1. The problem statement, all variables and given/known data Why Does 0 Velocity and Negative Acceleration = Increasing Speed? 2. Relevant equations None 3. The attempt at a solution I am using Halliday and Resnick (5th Edition), and the anwer key in the back says that speed is increasing at the point when velocity is zero, and acceleration is negative. I am assuming I am wrong and the book is right. I just can't understand it though. If the rate of change of the position function is not changing, and the acceleration is decreasing, then doesn't that mean that the particle is going in a straight line and is slowing down?