SOLUTION: A ball is thrown from a height of 160 feet with an initial downward velocity of 12 ft/s. The bald height “h” (in feet) after “t” seconds is given by the following. H=160-1

Question 1146590: A ball is thrown from a height of 160 feet with an initial downward velocity of 12 ft/s. The bald height “h” (in feet) after “t” seconds is given by the following.
H=160-12t-16t^2
How long after the ball is thrown does it hit the ground?
Round to nearest hundredth
Found 2 solutions by josgarithmetic, Boreal:
Answer by josgarithmetic(39630) (Show Source): You can put this solution on YOUR website!
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H=160-12t-16t^2
How long after the ball is thrown does it hit the ground?
Round to nearest hundredth
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simplify and solve this.
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
Hits ground when H=0
so -16t^2-12t+160=0
divide by 4
-4t^2-3t+40=0
4t^2+36-40=0
t=(1/8)(-3 +/- sqrt (9+640); sqrt 649=25.48
positive root only t=22.48/8=2.81 sec

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