Question

A ball is thrown straight up into the air. As it moves upward, its speed ____ by ___ each second. As it falls back down, its speed ___ by ___ each second.

Answer 1

A ball is thrown straight up into the air. As it moves upward, its speed **decreases** by **approximately 9.81 meters per second** each second due to the acceleration of gravity acting downward. As it falls back down, its speed **increases** by **approximately 9.81 meters per second** each second as it accelerates toward the ground under the same force of gravity.

In summary:
- Moving upward: speed **decreases** by **9.81 m/s²**.
- Moving downward: speed **increases** by **9.81 m/s²**.