Question 1188917
An object is propelled upward from 12 meters above ground with an initial velocity of 120 meters/second.
It's [sic] height can be modeled by the equation s(t)=-5t^2 +120t+12 meters, where t is time in seconds.
It's [sic] velocity can be modeled by the equation v(t)=-10t+120 meters/second, where t is time in seconds. 
At what velocity did the object hit the ground?
------------
Find t when s(t) = 0
s(t)=-5t^2 +120t+12 = 0
--------
Then solve for v(t).
=======================
PS  it's = it is