A child throws a ball into the air and then catches it when it comes down. What us the effect on the ball's potential energy? A. Potential energy increases, then decreases to the original level.
B. Potential energy decreases, then increases to the original level.
C. Potential energy remains the same throughout the ball's trajectory.
D. The answer cannot be determined from the information provided.

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.