SOLUTION: Please help me solve this word problem. If an object is projected from a height of 48 ft with an initial velocity of 32 ft per sec, its height h in feet after t seconds is given b

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Question 1006449: Please help me solve this word problem.
If an object is projected from a height of 48 ft with an initial velocity of 32 ft per sec, its height h in feet after t seconds is given by:
h=-16t^2 +32t +48
a.)After how many seconds is the height 60 ft?
b.) After how many seconds does the object hit the ground? (hint: when the object hits the ground, h=0)
Thank you so much!

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Two answers to height=60 feet unless it is the maximum.
-16t^2+32t+48=60
rewrite, subtracting 60 and changing all signs.
16t^2-32t+12=0
4t^2-8t+3=0
(2t-3)(t-1)=0
t=1/2 sec, 3/2 sec., it will be at height 60 feet.
-16t^2+32t+48=0
factor out a -16
t^2-2t-3=0
(t-3)(t+1)=0
t=3 seconds only sensible root.
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