Answer:
1.68 seconds.
Step-by-step explanation:
The question, is, essentially asking for time, t, at position 325 feet.
So:
Set h(t) equal to 325.
325 = 16t^2 + 168t + 5
Subtract 325 over, to get the quadratic:
0 = 16t^2 + 168t - 320
Factor out an eight, simply to make the equation easier:
0 = 2t^2 + 21t - 41
Now, use the quadratic formula to find the "zeros", or solutions:
{-21 + (21^2 - [(4)(2)(-41)]^.5}/(2)(2); {-21 - (21^2 - [(4)(2)(-41)]^.5}/(2)(2)
Simplify:
(-21 + [441 + 328]^.5)/4; (-21 - [441 + 328]^.5)/4
(-21 + [769]^.5)/4; (-21 - [769]^.5)/4
(-21 + 27.73)/4; (-21 - 27.73)/4
(6.73)/4; (-48.73/4)
t = 1.68, -12.18
It makes no sense for t to be negative, since t represents time.
Therefore, the potato is 325 feet in the air after 1.68 seconds.
I hope this helped! :)
