SOLUTION: A toy rocket is launched straight up into the air with an initial velocity of 60 ft/s from a table 3 ft above the ground. If acceleration due to gravity is –16 ft/s2, approximately

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A toy rocket is launched straight up into the air with an initial velocity of 60 ft/s from a table 3 ft above the ground. If acceleration due to gravity is –16 ft/s2, approximately      Log On


   

Question 1011455: A toy rocket is launched straight up into the air with an initial velocity of 60 ft/s from a table 3 ft above the ground. If acceleration due to gravity is –16 ft/s2, approximately how many seconds after the launch will the toy rocket reach the ground?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
H(t)=-16t^2+60t+3
find the zero where t is positive
-16t^2+60t+3=0
t=(-1/32){-60 +/- sqrt (3600+192); sqrt 3792=61.58
use negative root
t=(-1/32)(-121.58)=3.80 sec
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