SOLUTION: I don't know if I am putting this in the right area but I need your help I can not do this I have been trying for ever please help me? The height h in feet of an object after t

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Question 81421: I don't know if I am putting this in the right area but I need your help I can not do this I have been trying for ever please help me?
The height h in feet of an object after t seconds is given by the function
h=-16t^2+90t+3
How long will it take the object to hit the ground? round your answer to the nearest thousandth.
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the object "hits the ground" when it is at height 0 ... so set h=0 and solve for t

0=-16t%5E2%2B90t%2B3 ... using quadratic formula t=%28-90+%2B-+sqrt%2890%5E2-4%2A%28-16%29%2A3%29%29%2F%282%2A%28-16%29%29 ... t=%28-90+%2B-+sqrt%288292%29%29%2F%28-32%29

so t=-0.033 and t=5.658 ... the negative value is unrealistic