SOLUTION: Hi, Can anyone help with this word problem? The height h in feet of an object after t seconds is given by the function h = �16t2 + 20t + 5. How long will it take the object to hit

Question 80866: Hi, Can anyone help with this word problem? The height h in feet of an object after t seconds is given by the function h = �16t2 + 20t + 5. How long will it take the object to hit the ground? Round your answer to the nearest thousandth.
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
To find when it will hit the ground, set h equal to zero

Now use the quadratic formula to solve for t

Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=720 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: -0.213525491562421, 1.46352549156242. Here's your graph:

Ignoring the negative answer, the answer is:

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