SOLUTION: If a rock is dropped from a building 576 ft. high, then its distance in feet from thr ground t seconds later is a function defined by f(t)=-16t^2 +576. How long after it is dropped

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: If a rock is dropped from a building 576 ft. high, then its distance in feet from thr ground t seconds later is a function defined by f(t)=-16t^2 +576. How long after it is dropped      Log On


   



Question 528802: If a rock is dropped from a building 576 ft. high, then its distance in feet from thr ground t seconds later is a function defined by f(t)=-16t^2 +576. How long after it is dropped will it hit the ground?
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Set f(t) to zero and solve for t:
f(t)=-16t^2 +576
0=-16t^2 +576
16t^2 = 576
t^2 = 36
t = 6 seconds