1. The problem statement, all variables and given/known data A student throws a set of keys vertically upward to her sorority sister in a window 4m above. The keys are caught 1.5s later by the sister's outstretched hands. (a) With what initial velocity were the keys thrown? (b) What was the velocity of the keys just before they were caught? 2. Relevant equations 3. The attempt at a solution (a) 10m/s (b) -4.68 m/s I know how to get the solutions by using the constant acceleration formulas, but my question is with (b). If the velocity is negative, that means the keys have to be moving DOWN, because maximum height achieved by the key would be when the velocity is 0. So I'm very confused on this point. How could the key still be going up if its already negative velocity? Someone please point out where my thought process went wrong.