>You could not "let the truck" leave you behind by jumping straight up because you are moving at the same speed with nothing to slow you down because you eliminated the air resistance.

[I ask this hesitantly, having been out of physics class for several years, but]
Wouldn't the truck's thrust still have to be accounted for, in comparison to your lack of continual thrust as soon as you leap from the truck, or would removing air resistance be enough to compensate for this?

Penny*smiles with timid uncertainty*stamp