Problema Solution
If a stone is tossed from the top of a 190 meter building, the height of the stone as a function of time is given by h(t) = -9.8t2 – 10t + 190, 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 provided by our tutors
h(t)=-9.8t^2-10t+190
Set h(t) to zero and solve for t:
0=-9.8t^2-10t+190
0=-4.9t^2-5t+95
since we can't factor, we apply the quadratic formula. Doing so yields:
t = {-4.94, 3.92}
Tossing out the negative solution leaves us with:
t = 3.92 seconds