A simple program can solve this

[WhiteCube]

If I fire a bullet straight up, at 2000 km/hour, what speed will it be going when it returns to me?

Spoiler

I don't want to spoil this one, the answer surprised me.

 

[John Joe]

same speed?

 

[WhiteCube]

same speed?

Right. It just felt counter-intuitive to me that a falling object would hit at the speed of a bullet.

 

[John Joe]

interesting