The position function (in feet) of an object dropped from the top of a building 500 ft tall as a function of time (in seconds) is s(t) = 500 − 16t^2.

-> Find the velocity, in feet per second, of this falling object at t = 2 sec.
-> How long, in seconds, does it take the object to hit the ground? (Round your answer to one decimal place.)
-> What is its velocity as it impacts the ground?