## Conceptual Physics (12th Edition)

The acceleration of each ball is $10 \frac{m}{s^{2}}$ at all times, directed downward. Freefall acceleration is discussed on pages 46-49. One second after being thrown, ball A is at rest. One second after being thrown, ball B is moving at 5 m/s upward. One second after being thrown, ball C is moving at -7 m/s, which is a speed of 7 m/s directed downward. Ball C is moving faster than any other ball, because speed is the magnitude of the velocity, irrespective of direction.