## Conceptual Physics (12th Edition)

This is discussed on pages 46-47. Whether it is rising or falling, the acceleration of a freely falling object, in the absence of air resistance, is always $10 \frac{m}{s^{2}}$ directed downward. Each second while going straight up, the baseball's speed decreases by 10 m/s. Each second while dropping straight down, the baseball's speed increases by 10 m/s. With no air resistance, the time going up equals the time coming down.