Max Height of Ball: Can it be Determined?

[sparkle123]

Homework Statement

A batter at a baseball game hit a ball such that it flew into the stands. The ball was caught by a fan when it was moving at 10 m/s at a height 20 m above the height it was hit. What was the maximum height to which the ball rose before falling back down towards the fan?

2. The attempt at a solution

The official answer is "The maximum height cannot be determined. "
I thought it could be determined by noting that the total mechanical energy is the same at the max height, 0 m/s equaled the energy at 20 m, 10 m/s.
What am I missing?

 

[ojs]

No, the velocity at the top is not 0 m/s, that is only the vertical part of the velocity, the horizontal part is a constant and we don't know any angle here so we can't distinguish the two.

 

[sparkle123]

You're a genius! Thanks!