SOLUTION: The height h in feet of an object after t seconds is given by the function h = –16t2 + 60t + 9. How long will it take the object to hit the ground? Round your answer to

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Question 68905: The height h in feet of an object after t seconds is given by the function
h = –16t2 + 60t + 9.
How long will it take the object to hit the ground? Round your answer to the nearest thousandth.
I have come up with 3.894 sec. Is this correct????
Answer by tutorcecilia(2144) About Me  (Show Source):
You can put this solution on YOUR website!
I agree with your answer.
I used the quadratic formula to solve for x.
Let 0=–16t^2+60t+9
Solve by using the quadratic formula:
x=-.144 or x= +3.894436803.
Eliminate the negative answer.
Rounding the positive answer = 3.894
Check by plugging 3.894 back into the original equation.
The answer is very close to zero (.028224), so it checks out.
.