SOLUTION: If a stone is tossed from the top of a 250 meter building, the height of the stone as a function of time is given by h(t) = -9.8t2 – 10t + 250, where t is in seconds, and height is

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Question 493741: If a stone is tossed from the top of a 250 meter building, the height of the stone as a function of time is given by h(t) = -9.8t2 – 10t + 250, where t is in seconds, and height is in meters. After how many seconds will the stone hit the ground? Round to the nearest hundredth’s place; include units in your answer.
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
h(t) = -9.8t2 – 10t + 250
set h(t) to zero (ground level) and solve for t:
0 = -9.8t2 – 10t + 250
0 = 9.8t2 + 10t - 250
0 = 4.9t2 + 5t - 125
applying the "quadratic formula" we get:
t = {-5.59, 4.57}
we can throw away the negative solution leaving:
t = 4.57 seconds